Thats a GSX and a Spider.
RS- Rally sport, base model. Lowest version of the Eclipse,420a engine by chrysler group
GS- Grand Sport, best non-turbo model, 420a engine by chrysler group
GS-T- Grand Sport Turbo, turbo FWD model of the Eclipse, Mitsu's 4G63 engine
GSX- Grand Sport Cross, turbo AWD model, highest, Mitsus 4G63
Those names apply to 1st and 2nd gens, first gen lasted to 1994, 2nd gen lasted to 99. 3rd gen is not worth getting.
You could always get an Eagle Talon, which is the same thing as the Eclipse but under a different brand. Package codes from worst to best go as follows, base, ESi, TSi, and TSi AWD. Plymouth Lasers were also around in the 1st gen, which was the same thing as Talon and Eclipse.