gsxr 1000 seat unit

right im ment to be getting my k2 1000 resprayed in the tas relentless colours soon,but before i do i was thinking of doing a little body styling,i want to change my seat unit for one from a newer gixxer but not sure if it will fit.i would like one of something around the k5 its the unit that flares out they look cool.would it fit straight on or would i need to change the sub frame to.recon it would be worth the hassle when its all done