Ofna 10245 works good, small, compact and uses two stick packs.
Mugen box works good to, but you will have to grind the edges of wheel, and its almost 3x the price of the Ofna.
Here is a pic of the Ofna
A bad day racing is still better than none at all.
TAMIYA TRF Racing Factory
CWRCB-Central Washington R/C Boat Club, RCUnlimiteds