No, not set on the 18". I am actually going to be putting a 19" on the rear. My ice tires from my previous bike are 19" and would like to use them on my 250fx so would actually only need the hub and brake carrier for the rear. I have a 19" wheel already.
Likely not going to need anything though as I found Cooper's in Edmonton has a awesome deal on tusk wheel packages and I can get a full set laced with bearings for around $800. I hate lacing wheels so likely gonna go this route.