I'm buying a 2006 CRF450R. Mine will mostly be for the track. I don't know much myself but you can check out the supermotojunkies forum
Have you done any trackdays?I have a 2016DRZ400SM. It is the bike I ride most on the street (I use it for commuting). Great bike. I love riding it around town more so than my zx10r. Feel free to ask any questions.
May want to look into a fz-07. Can find great deals on like new ones on CL.
I have done only one. I use a ninja 300 and zx10r on the track mostly. But the DRZSM is really a heck of lot of fun on the track. The suspension is lacking, but that is to be expected. But I was able to keep up with a faster intermediate pace through the turns, not so much on the straights. I love how light weight and narrow the bike is. It is a heck of a lot of fun. I am not able to stick a foot out and slide the rear end or anything close to that lol. All I have done to it is stainless lines, exhaust, and rejetting. But to be honest, I ride it on the street because it is so fun to run through gears and go around WOT everywhere. On the zx10R, 1st gear goes to the same speed drz400sm tops out at. So it is much more appropriate for street riding and staying out of trouble.Have you done any trackdays?