Id go GSXR
IF you can restrain yourself and be sensible learning the bike then Id go 600 sports bike, just be careful.
I passed my direct access in a month then jumped on a CBR 600RR5 , everyone said I be dead in a month
but thankfully I took my time and rode it in all weathers, if you respect it and the conditions youll be fine.
I didnt find it any harder than the 600F I did my test on, but then I didnt really fully push the bike for a long time lol
(I got an experienced friend of mine to cane it so that is was ran in properly
)
Takes its toll on your back/shoulders and wrists so if you have any issues there Id stay away from a sportsbike.....
I remember nearly dropping it outside the dealers