YOOO i'm a college student too...
I was shopping around for those exact cars and i found myself in a GSR. the SI is mint, but i agree it's just a toned down GSR, i think they're ricer too- its just missing that real race car edge i think. i LOVED the 5th gen Preludes alot, i found them really easy and enjoyable to drive, I like their size and look as well. i never liked small cars much cuz i'm 6 foot. but when it came down to it i was drawn to the GSR for a few reasons:
-it's cheaper
-it feels more like a race car
-its much much more nimble through
all the annoying traffic around here (new haven, CT)
-mods are cheaper
-the handling is more crisp
-THE HATCHBACK ALLOWS SHITLOADS OF ROOM
- i fit in the cockpit mint
- girlies dig it just fine

who cares if mad heads have similar cars, GSRs are on the rare side those who know will notice your ride, and its a good sleeper tactic cuz they look similar to nonVTEC.
Personaly i'd like to be different through modifications- to show your aftermarket knowledge and taste.. any dumby can buy a car they don't see often...
Preludes are more expensive, but they do have a beefier feel... its up to ur taste really. DRIVE'EM ALL! but i say with the cheaper GSR you'll have some cash to set it apart from the flock right!