Wheels for my Blue Beast

[Math]

I've just bought a 2001 wr 426f with a dual sport lightning kit from baja design to be street legal. I wanted to buy a second wheel set (rims, brake discs, sproket...) to have one mounted with off road tires and a second one mounted with street tires but it is too expensive: about 650$ U.S. per wheel. What kind of used rim would fit? Are all YZ wheels from the 90's ok for my bike for example?