CraigHickman has a good picture of a crab module and a drive train assembly on his site. You could also PM him to ask him how he did some of the more intricate work.
http://www.xtremefury.com/craig/
I too highly recommend that your team does the CAD from scratch. Use a few pictures as reference, but do your own design. Knowing every nut, bolt, washer, sprocket, chain, and spec of dust you put into your drawing will make it that much easier to come up with design improvements. If your team is new to CAD, I would recommend doing the tutorials first, then doing a simple aluminum frame. Then from there you can experiement.
As always, many of the FIRST motors, transmissions, pneumatics (etc) are already available at
www.firstcadlibrary.com