youll probably get alot of people telling you to do a search, but ill try to post the little bits i understand about the car(i have a 89 N/A)
the S/C models i believe were all the same car, maybe some small variations, like the LED taillight, but nothing to big to worrie about, a good and bad thing(at the same time) about the car is that it had a suspension that was more prown to understeer, which made sence overall, but the problem is and was that the mki(and maybe mkii) mr2s are known for having a bit of flex in the suspention(Macpherson strut) causing the wheels to toe in/out(mainly a problem when the rear wheels do this) this can be minimalized by either upgrading suspention components(spherical bearings) or by making the suspention sway less(stiffening rear suspension), but instead toyota had it setup so that the rear still swayed just as much as the N/A, but with (i believe but not sure) stiffer compression in the front shocks, anyways this led to the car having predictable understeer near the limit and then at and over the limit the car would change toe in the rear tires and the car could spin very quickly, so its not the easiest car to drive at the simit with stock suspention components, but i also havnt heard any horror stories, so dont dwell on it, just know its possible
if your planning on modifing the car this isnt really a issue
Other things:I have T-Tops(all S/Cs did) and id recommend them if you like that sort of thing, dont worrie about rigidity too much, the cars not bad to begin with, and theres tons of ways to stiffen it if you really want to
The 4agze(supercharged mr2 engine) is probably the best bang for the buck power wise, a pulley alone can get you up to 160 something whp, only downside is the sc12 supercharger does start running out of steam at higher power ratings, but the 4agze block is a good place to start a Turbo fabrication(again best for the money for doing a turbo)
Really sweet engine noise coupled with a supercharger=sounds like a jet!
really reliable up to 200k, after that it usually depends on owner
ive loved every minute of owning my 88SC. at first the understeer seemed like too much then when you get used to driving the car its very easy to make the car do exactly what you want it to do. and as said before the engine is GREAT. i love the 4agze its just got so much low end power its amazing. and then there are the brakes this car is one of the best stopping cars ive ever driven you just down shift and ease on the brakes and you can stop on a dime
but then there are the bad. like any 18 year old car its not going to be perfect. the t-tops are prome to leakage (mine dont too bad but ive heard of cars that cant be driven in the rain at all) my engine has a oil leak near the oil filter because of a bad seal (getting it fixed this weekend) but its very minor. the suspenion will most definitly be worn out. and then there are the horror stories of rust (none on my car) but if you live in a rainy area then you might have a problem.
as ottobon said the cars sound like jets BUT there are those rare mk1s that dont sound too great (like mine) ive seen many mk1s where the exhaust sounds terrible past 3000RPMs
and again very reliable cars. i have 151,xxx miles on my car and it hasnt given me any issues (besides the oil leak) it just runs great still has all its power