Thanks, everyone, for all the information so far! I know this must be the sort of thing you go through each time someone shows up for the first time with a "new" compact Mac, but I really appreciate the help.
So, let me double check all this:
1. I'd really like to have greyscale graphics, but that apparently requires having both a rare greyscale harness for the CRT *and* an also-rare graphics card, which has to be one of a few select models that is compatible with the harness. Does this also increase the max. screen resolution, or just the color depth? I'd really like the greyscale graphics, but this sounds like it may not be worth the cost, especially if the internal resolution is still limited to 512x342.
2. Ethernet card may be of interest, but will take some software fiddling to get it to work with a modern LAN. Our Internet access is via high-speed DSL, which is split out to the main house and two apartments. Then, in our apartment, we have a Time Capsule connected to further split the connection out to the devices in our home. In order to work properly with the rest of the network, the Time Capsule's router functionality is configured to be little more than a passthrough. I can do whatever I want to the Time Capsule, but I have no access to or control over how the DSL modem or the ethernet hub at the center of the network are configured. (Basically: we live in a 1-bedroom cottage that shares a lot with a larger house and another cottage. The owner lives in the main house, and has a high-end DSL connection which is shared out to the cottages via a hub in the main house connected to professionally-installed wiring to the rental units leading to wall terminals). Will this setup be problematic?
3. If getting online is still viable given #2, I have heard of three different types of devices: a PDS ethernet card, a SCSI ethernet adapter, and an AppleTalk bridge. The lattermost seems like it would be a bit problematic to get working with TCP/IP, but are there any specific advantages or disadvantages between the first two? Obviously a PDS card would be less cluttery, but also take up the PDS slot. Is a SCSI adapter slower (or even compatible)? Would it work in a SCSI chain (if I decided to add, for example, an external CD-ROM drive)?
4. From what I've read so far, using a web browser is still pretty painful unless an accelerator card is also installed. And if I understand correctly, it's better to use an 030-based accelerator than an 040, for the sake of software compatibility. Are these still available anywhere? Any recommendations, or makes/models to steer clear of? Also: it seems like some of the accelerator cards have PDS pass-through slots. Would this allow me to chain the accelerator with either a graphics card or an ethernet card, or does that start posing a logistical problem? (both space and power draw)
5. Alternatively: are there any viable drop-in replacements for the CPU, or is a full accelerator board necessary to handle a higher clock speed?
6. Are there any practical advantages to replacing the ROM SIMM with a 32-bit clean one rather than just installing Mode32? Are there any compatibility or performance differences? I'm not looking to run OS8 or anything, but I do definitely intend to upgrade the RAM on both units (one has 4 and the other has 8 MB).
I think that's about it for right now. Thanks again for all the help so far!
So, let me double check all this:
1. I'd really like to have greyscale graphics, but that apparently requires having both a rare greyscale harness for the CRT *and* an also-rare graphics card, which has to be one of a few select models that is compatible with the harness. Does this also increase the max. screen resolution, or just the color depth? I'd really like the greyscale graphics, but this sounds like it may not be worth the cost, especially if the internal resolution is still limited to 512x342.
2. Ethernet card may be of interest, but will take some software fiddling to get it to work with a modern LAN. Our Internet access is via high-speed DSL, which is split out to the main house and two apartments. Then, in our apartment, we have a Time Capsule connected to further split the connection out to the devices in our home. In order to work properly with the rest of the network, the Time Capsule's router functionality is configured to be little more than a passthrough. I can do whatever I want to the Time Capsule, but I have no access to or control over how the DSL modem or the ethernet hub at the center of the network are configured. (Basically: we live in a 1-bedroom cottage that shares a lot with a larger house and another cottage. The owner lives in the main house, and has a high-end DSL connection which is shared out to the cottages via a hub in the main house connected to professionally-installed wiring to the rental units leading to wall terminals). Will this setup be problematic?
3. If getting online is still viable given #2, I have heard of three different types of devices: a PDS ethernet card, a SCSI ethernet adapter, and an AppleTalk bridge. The lattermost seems like it would be a bit problematic to get working with TCP/IP, but are there any specific advantages or disadvantages between the first two? Obviously a PDS card would be less cluttery, but also take up the PDS slot. Is a SCSI adapter slower (or even compatible)? Would it work in a SCSI chain (if I decided to add, for example, an external CD-ROM drive)?
4. From what I've read so far, using a web browser is still pretty painful unless an accelerator card is also installed. And if I understand correctly, it's better to use an 030-based accelerator than an 040, for the sake of software compatibility. Are these still available anywhere? Any recommendations, or makes/models to steer clear of? Also: it seems like some of the accelerator cards have PDS pass-through slots. Would this allow me to chain the accelerator with either a graphics card or an ethernet card, or does that start posing a logistical problem? (both space and power draw)
5. Alternatively: are there any viable drop-in replacements for the CPU, or is a full accelerator board necessary to handle a higher clock speed?
6. Are there any practical advantages to replacing the ROM SIMM with a 32-bit clean one rather than just installing Mode32? Are there any compatibility or performance differences? I'm not looking to run OS8 or anything, but I do definitely intend to upgrade the RAM on both units (one has 4 and the other has 8 MB).
I think that's about it for right now. Thanks again for all the help so far!