4 * 4MB + 4 * 1MB SIMMs = 20MB. 4MB 30 pin SIMMs are significantly cheaper than 16MB SIMMs and should give enough RAM to experiment further with the SE/30, even when using Netscape.

If that works for you, 4 * 16MB + 4 * 4MB = 80MB is almost perfect, and a lot cheaper than 8 * 16MB.

The Asante ethernet card should work well. If you have problems, ask. Make sure that you install the drivers using the installer utility. Some more tips can be found at http://www.vintagemacworld.com/netprimer.html and elsewhere.