dont write off the idea of an RVF, deals are out there.
my mate has one, he paid 1200 for it! it was VERY shabby, but panels are available from Tyga and i grafted a cagiva mito rear end on it (copy of a 916) and it looks the muts!.
the FZR is ok, go for the SP model if you can.
the fastest and most tunable is the ZXR.
the hondas with gear driven cams sound nice but you cant skim the heads if you ever wanted to, theyre also a bit of a 'mare to get the carbs in and out being a V format.
every GSXR4 ive ever known has had electrical problems.....

if it was me tho i think id spend a grand on a CBR4 (NC29) just for the looks....