[RC-Monster Mike]

Just be careful with the bullets. In the very least, label them with different colored tape to avoid the inevitable reverse polarity. The problem with bullet connectoers (besides the obvious possibility of reverse polarity) is that they wear out faster from being plugged/unplugged continuously. This isn't drastic wear, but the Dean's is more resistance to losing spring tension. Personally, I think the Dean's plugs are just easier to use and will perform just as well as the 4mm connectors someone has you sold on. Do you already have the 8xl motor? This or the 7xl would both work very well on a heavy truck such as yours. The 9918 will handle this duty, but your gearing is way too aggressive for normal running. If you are set on using the 51 tooth spur gear, get the smallest pinion you can find (10 or 12 is a good place to start!). 15/66 or similar is a good place to start with the stock spur gear. You didn't mention what diffs you use, either. This will effect your gearing range selections well.
Schultze will repair your controller (and blame you for the damage), but it will most likely take quite a bit of time (3 months sounds about right). I don't think the repair will be much, based on your description of the failure. Likely less than $100.