i'd be weary of buying a car with that much modification done to it. make sure to test drive, do a compression test, and leakdown etc... find out if the owner raised the redline from the stock B18B's 7000. if so, find out whats been done to strengthen the motor.

as for RS, you wont be missing out on much at all, unless you tend to have a late reaction for braking and cant help but lock your brakes occasionally. then you'd want ABS. it will be a lot of work to put in ABS, not really worth it to me. as for the sunroof, its fun to have and pimp around town, but adds weight, is a good place for rust to gather, and the chassis is less rigid with a hole in the roof. besides, the novelty of having a sunroof wears off after a few months, it depends on how much you want it. and DO NOT, I REPEAT, DO NOT try to modify a sunroof to the RS!! the car will twist over speedbumps and you'll literally feel the floorpan stretch and bend under you going up and down steep driveways and entrances!

ps... thats actually a good price for an integra with LS/VTEC. anything drastically cheaper, i'd think there could be some reliability issues that the owner could be hiding. just make sure to do a lot of research.