All 2st Motard Help

Howdy! First time post here, so go easy on me.

I have recently moved from a 2005 Husaberg FE450 to a 2012 WR300. It's taking some getting use to, but I'm having a ball.

With the warmer weather coming up, I am considering fitting a set of road rims and tyres. But I need to do it on a limited budget.

From what I've read I need a 3.5" front rim and anything from a 4.5 to 5" rear. I have been looking at sets of CBR250rr and VTR250 rims, but I'm concerned that there are differences in the wheels, from different years, that I don't know about that will effect the fitting.

So, can someone give me a run down on what to look for when buying rims to suit? Getting spacers made up isn't a drama, but I need to make sure I have the right rims, sprockets, discs etc to start with.

Still looking for info if anyone can help?