Well first, there is quite a bit of information in the suspension section. Overall, something 7.5-8" wide, with about a 50 offset, and a 225 wide tire should do you pretty well.
You seem to be the authority here on wagons. I just got an 04 and want to do some wheels and tires and leave the car stock, this is just for appearance's sake. I just got out of a highly modded 350Z and just need some peace for a while! I'll get into seriously later, but in the meantime, I need to cut down the Soccer Mom factor with some wheels and tires, but I cannot find the difinitive list of what sizes will work. Any guidance?