Having ridden most of them, and owned a number of ZX9Rs (all E/F models):
ZX9R - fantastic road bike, big enough to be comfortable, great engine, and they do handle well when set up (the rear needs lifting up). Can run in the fast group on track days but if I were doing mostly track I'd go for the blade.
CBR - fantastic all around bike, very Honda-esque in that it seems just a very strong package. I personally found it a bit too clinical feeling, and they're also quite small which as I do a lot of miles didn't suit either myself or the gf.
GSXR - Somewhere in the middle, but with a more powerful engine than either!
No matter what you buy at this kind of point budget for a suspension rebuild/replacement and likely a brake rebuild/master cylinder upgrade - these will all be miles away from working as they should at this age and they will materially change the feel of the bike if sorted.
