Alright first off what you should be reading is the SOGI web page, just search the tech center but don't put anything in the search feild...
http://www.supras.com/sogidb/index.php
Then if you still have some questions search....
http://www.supraforums.com and
http://www.supramania.com forums
For general information on how stuff works go to...
http://www.howstuffworks.com/
Since it is an N/A then one day you'll want more power, if you want anything over 275-300 then just go ahead and do the turbo swap, most people swap in a 7M-GTE (stock MK3 turbo engine) but some swap in the 1JZ-GTE (stock JDM MK3 2.5L twin turbo engine), and even more rare are people that swap in a 2JZ-GTE (MK4 twin turbo engine). As for what parts are made for the car, pretty much anything you will ever need.
http://www.suprasport.com has the biggest selection of MK3 parts (you have a 86.5-92 MK3). Carbon Fiber FX has also been coming out with alot of MK3 parts lately too.