Where are you from?
For states go Jaco/TRC/Parma/BSR
For Europe another option is GP speedtyres(http://www.gp-speedtires.de
) for donuts and glued on rims(1/12, 1/10 and Touring for electric and 1/8 and 1/10 gas), or ellegi racing only sells touring car foam I believe.
I use GP because they are good, cheap and I can glue them myself, it is very difficult nowadays to find donuts and I find all other brands to come loose after a few runs...
Make your pick