This will look like a repeat of Mattstang04 above post, but I think you were looking for brand names...I went after handling on my 2K GT convertible as well. I did all the work myself in my garage.
-I kept the stock springs and ride height due to the steep grade/angle of my driveway and some of the rough mountain roads hereabouts.
-installed SR Performance front and rear swaybars with poly front bushing kit (this made the single biggest noticeable "change" in the firmness of the car).
-Installed SR Performance front/rear shock tower braces.
-Installed Southside Machine/GForce subframe connectors (these are bolt ins, but very beefy and bolt in at the front Kmember and the rlca positions unlike most others on the market).
-Installed Koni STR.T struts/shocks (I purchased from Shock Warehouse...I missed it, but they do run specials on Koni from time to time).
-Installed new upper and lower rear
control arms from Maximum Motorsports (uppers are Ford Performance units with rubber bushings at both ends...buy their bushing tool for the removal/install of the differential bushings--makes it easy...lowers are HD with poly bushing on the chassis end and spherical on the differential end).
-I have BFG Gforce tires, but there are probably dozens of possibilities out there that are as good. (18x9 rims...255/40zr18 front/275/40zr18 rear).
These combined (maybe miraculously) to make a much more planted and go kart like car. Future plans include front ca poly bushings and steering rack bushings. Other things that changed the "feel" of the car include an MGW shifter and replacement seat foam for the driver's seat. Enjoy.