Rules for new riders:
600cc=Would like to kill you... Do something stupid and it might do it..
1000cc=WANTS to kill you... Do something stupid and IT WILL KILL YOU!
1300cc=Your a DEAD MAN RIDING.. No brainer, just buying the bike as you first ride was stupid enough...
a 600 is very very fast.infact a 1000cc bike has trouble keeping up with it in the first 2 gears.
Yamaha R-1 is jack shit(i used to love the R-1) compared to the rest of the other bikes,the only reason it sells the most is becos of its looks,as for the r-6 its old news ,used to be good now its no where near the zx-6r .
anyway if you're looking for a zx-6r it should cost you around 9+,whereas a 1000cc will be more than 11 brand new easily .
there are other older bikes which may be good for you.do some research and figure it out what you want ,but my advice is do not buy a 1000cc bike if you wanna stay in one piece.