pic: Coax Crab, another variation.

[SgtMillhouse648]

looks very nice! what are you making the yokes out of that hold theh wheels? This looks very similar to our setup, and we made our yokes out of .25" steel plate, and had numerous problems with them bending right below the uppermost axle. There are 2 ways around this:
1: Go to more of a wildstang setup and support the system on the bottom as well
2: Run a pair of straps around the wheel right where the lower axle is. This would join the forks together, and give you more support on the bottom side where it would be prone to bending

Also, how do you plan on on tightening the chain to drive the wheels themselves, or do you plan on using spur gears like the beast does?
I would personally swap your setup between the steering and the drive: aka, use the timing belt for the drive of the wheels, and the chain for the steering, but that's just my opinion. Good Job, that is a real nice looking setup though.
Malhon