Something you might want to look into instead of a shift kit would be a tune with aggresive shifts programmed in. I looked into shift kits for my 02 and decided instead of messing with the transmission I would just buy a chip with the tune on there. With the chip my car would chirp shifting from 1-2 and the rest of the shifts were very firm. When I went with my XCAL2 you can actually adjust how hard you want it to shift, on the setting my tuner sent me 1-2 on the 16's would throw me sideways and it chirps 2-3. On the 18's it just catches.