Roadmaster 49 - I purchased the Dexstar AM20766 wheels for my 1954 3601 Truck and they work just fine. If you are looking to get the same size tire ( height ) as original then you might consider LT215 / 85 / R16 . FYI, I spent $300 total, including shipping for all four rims from etrailer.com
Hope this helps and YES keep the truck, you'll enjoy it and the challenge.
Ronnie