i don't know w/c way u wanna go, looks or performance?
23lbs is not that bad on r18's (i had 27lbs on mine at one time would u believe). a bit heavy on acceleration and a tad less mpg but i'll definitely go w/ the 18's compared to let's say, 17's. 18's definitely looks hotter than the 17's imo.
by the way, your car looks like ayenoc's car. check it out...
EDIT:
your car.
Ayenoc's car.