Ditch the crappy 14" rims. Period. They are horrible to find tires for.
You can put Vanagon alloys on there 15" and also there are a lot of Audi and Mercedes wheels that will fit as well (with little work). Check out
www.vanagon.com in thier tech area.
As for tires then get some 215/75/R15 Sears has a deal for $79 each for Michelin XCX (LTX) tires which are hard to beat.