I'm pretty sure that the side panels and hood are the same dimensions...
The fenders (#10 in the parts dwg), from what I understand, are different on the Rush and the RMK... the fenders on the RMK are slimmer for less bodywork in the snow when sidehilling etc.
I'm not even sure the Heritage blue side panels are painted... looks like a wrap on a black side panel... If that is the case, you should be able to get just the wrap, or someone will make them for you (like ArcticFX).
The hood is super spendy ... in the $400 range... Maybe more for the limited build white ones. The hood, from what I'm told, is not TPU but a nylon compound like the belly pan and would be super difficult to get paint to stick. The TPU side panels are easy to paint with standard body shop grade paint supplies.