Here's the link to my build that Neil was talking about...
http://rctruckandconstruction.com/sh...ighlight=kitty
The drill motors you are talking about will be great for power but unless they already have, or you make a 90 degree drive for them you may struggle to fit them in. You would most likely need a further reduction on then as well unless you want a really fast trackloader. Sabertooth ESC's are a good choice but there are other choices. I have used Sabertooth 2x12's in all my builds with good success. The nice thing about using that sort of ESC is that they were made for tracked vehicles and setting up your TX is a breeze. You will need another ESC for the pump but everything can run off of the same battery.
Keep us posted!