To summarize, ANY drive will work, and the only limitations to consider are the 128 gig limit and the filesystem limits.
You can put in a larger drive, but the machine will only see 128 gigs; I often use 160 gig drives so I can get the FULL 128 gigs, because 120 gig (10^9) drives actually give about 110 gigs (2^30).
If you make a modest HFS partition at the beginning of the drive of, say, 1 gigabyte and install Mac OS 8.1 on it, you can then use as much of the remaining disk with an HFS+ partition.
All modern drives will run at the slower IDE bus speed. Also, there aren't any drives these days which take more power than the old, original drives. Most take a lot less, even at 7200 RPM.
You can put in a larger drive, but the machine will only see 128 gigs; I often use 160 gig drives so I can get the FULL 128 gigs, because 120 gig (10^9) drives actually give about 110 gigs (2^30).
If you make a modest HFS partition at the beginning of the drive of, say, 1 gigabyte and install Mac OS 8.1 on it, you can then use as much of the remaining disk with an HFS+ partition.
All modern drives will run at the slower IDE bus speed. Also, there aren't any drives these days which take more power than the old, original drives. Most take a lot less, even at 7200 RPM.