what a beauty! Rockauto can be your friend for these cars, most of the oem suspension bits i did at home with their stuff. for seats? I greatly suggest seats out of the MA60 supras, theyre super comfy and fit the car perfectly! I also agree on the preferernce for it over an ae86, the rear just looks a lot more aggressive, not to mention various shared parts like rear axles being the same, and such. I'd say, first things to do are to do a total fluids change just to start off fresh (try running stuff with zinc content as they are supposedly able to run a lot nicer with that stuff, ie Shell Rotella T4 Diesel Oils) and then get yourself a feeler gauge and fine tine the rocker arms, those are a common service item on the 22re engines. you could then test TPS signals to get a good idle, then i think youre all set!
Maybe buy a shifter bushing kit since ours are notoriously worn most of the time.