I just entered "Orion Foam Tires" for a search--here you go at $9.49 a pair (6 options all in stock).
http://www2.towerhobbies.com/cgi-bin...es&FVPROFIL=++
Sorry to learn about your RC. I only took the big one out for a spin since it still hit 100F today. Currently, Yahoo shows 95F and it is usually at least 5-10F low. BTW, I do have a photo of one of my cats embroidered on the leather head rests.