How is the stock rusty with the VXL system? There have been some reports here that it runs kinda hot. Of course, if geared down to a more modest 40mph, it probably would run cooler...
Before you purchase anything, I would see what your LHS supplies for parts at the store itself. It's nice just to walk in and get what you want without having to wait a few days for that itty-bitty part that is required to run!