Well, I assume that since you posted on a Hardware forum you are open to input? If so, all SCSI controllers need termination; on a SCSI I/II bus (cable) you have a "narrow" or 8-bit termination; passive termination uses just resistors to control erratic signals. This easy to do with "on device" termination, often abbreviated to, "TE." On a "wide" bus (16-bit), you need Active Termination which is best done "on cable."
Power supplies can be found in AT & ATX Format and will either require you to slice in a harness or buy one from Amigakit. Brand names tend to have better build quality, but again Amigakit sells one at 250W for under 20 US.
I'm not sure you need an extra fan, but you'll have to find a place for it in your case
