I did some fiddling around last night and I also rechecked my math. I am pretty sure I can use the original power supply. I can't imagine that my router could really draw 2.5 amps so that puts me in the green. Unfortunately I am going to have to cut a bigger hole in the case than I thought, the Zip drive will not fit in front of the power supply so I will have to mount it on the harddisk side of the LC and cut a new slot to insert the disc.

My only challenge now is hooking up that Zip, its not an apple branded drive so i'm not sure it will work at all or if I will have to change some pinouts.

Speakin of pinouts, I was looking at them on technick.net and I couldn't find one to take internal scsi (50 pin) ribbon cable and put it to DB-25. Also, How do I tell if a device is differential vs. single-ended?

Just as a heads up, i've never built anything more complicated than a battery charger.