rkman, hate to tell you this, but those front and rear bumpers are going to kill any kind of performance, they'll hit the rocks before your tires. If you're just building more of a pretty truck, it's okay, but I went as far as doing behind the axle steering on the front to get the best possible approach at any time. My servo mounts are rock solid too, they're tied into the axle braces and aren't going anywhere without having the axle ripped in two.

I personally run my MX-3 on my Clod, and use the 3rd channel to ghetto steer the rear. It's only a toggle switch, so the rear is either all left or all right, with no in between straight. Nice thing about having it independant from the front (even if it isn't the best way to do it), is that you can just swing the rear when taking on something, or crab walk (all 4 wheels pointed in one direction) to hit it from a different angle.

For a "controller" though, I run the tried and true Super Rooster with dual Integy 55x1 comm lathe motors wired in parallel.