What's your total budget?
What Sick says is true, for the most part, but they ARE out there, and as long as you go into the endeavor knowing that you'll have to do work, you'll be fine.
There aren't a ton of us 1st genners left, but a lot of them (excluding me i guess) have been around for awhile and are pretty helpful. I kindof got the "crash course" on these things, and i'm not planning on going anywhere soon.
As for other cars, depending on budget:
88-89 Celica AllTrac (harder to work on, more expensive parts, but a bit more robust, about the same commonality)
323 GT Sedan/323GTX (Probably no different from 1g GT MX6, and the GTX will be even harder to find and get parts for)
1G DSM (probably your best bet in terms of finding a good one and parts availability)
Pontiac Sunbird Turbo (not as reliable, cheap parts, and still decent availability on parts)
Any old Saab Turbo (probably what i would do if i wanted a turbo DD again)
MKiii Supra Turbo (more reliable than they get a rep for, parts aren't bad, and they're pretty easy to work on, can get REAL fast in a hurry)
Depending on budget, don't rule out the MR2 Turbo. Decent early examples can be had for $3-$4k depending on location. They aren't the easiest things to work on, but not hateful, either. Parts can be somewhat expensive, but they're pretty reliable as long as you keep up on maintainence.