CJS, this is the second time I think I have corrected you now, there are no gas-a-just struts, only shocks, both my supras have them for the rears, and I would gladly sell my left testicles for them to have made a strut, but they dont.
Chris,
If you want handling, I would personally get a $200 front coilover kit and MR2 struts, hack off the bottom spring perch from the stock strut housing, weld the sleve on, and shorten the strut housing up an inch or so to make MR2 struts fit with less of a spacer needed underneath. For $200, you will get bottom and top perches, nut, sleeve, and any springrate Eibach spring you want. That will get your front taken care of springrate and height wise...
For the rears, I suggest getting a few different kinds, ask around some ausies for rear spring options, seems there are a few manufacturers over there. What you dont use, you can probably sell to someone on the forums... Supression, I would see what will fit, someone mentioned Beemer 36series rears do the trick, but I dont know firsthand.
As for swaybars, custom will be the only thing if you are looking for EXTREME handling. Addcos may do the trick, but I have my doubts. For real tuning, you will want something adjustable....
As for rim and tire widths, ask anyone who knows anything about making a car handle, and they will tell you that there is really no upside to having 10" wide rears and 8" fronts on a well balanced car. I run the same tire size front and rear on stock rims, running my rear end just slightly stiffer than my front supression wise, on stock springs, and it makes the car run true from about 90% throttle down to about 20% throttle, either extreme, and it oversteers slightly, but always controlable. 10" wide rear tires would make my car push like a Pontiac Bonneville (my pre-supra).
Honestly, I highly suggest you spend $20 on a little book called "How to Make Your Car Handle." by Fred Puhn. That is the suspension tuner's bible. I personally own one, an LIVE by it. There is a deal on amazon.com, $26 after shipping gets it and "The Secrets of Solo" same author, giving in depth pointers on solo and solo2 auto racing.
Almost everythign you will want to know as far as suspension setups go is in that book. For the price of what you will pay for these mods, buy that book, as I feel I am just relaying his information down on a forum...
--BillyM