I have a set of 17" Stockton steelies on my wagon, 17x8 with 245/45/17 in front, and 17x10 with 315/35/17 in back.
They will take the same hubcap your wagon currently has on it.
I've been thinking about making a change, if you're interested let me know.
Mine handles fantastic with bigger t-bars and sway bars f/r. 25mph ramps at 45-50, it just hunkers down and goes.