In 2011 we used
9232T191. Most electronic parts can be held down with zip ties (speed controllers, digital side car, wires, etc). The .1875" hole diameter it allows for a #8 to pass through with lots of room, #10 with a very tight fit, and 1/4" if you drill out the hole. I think we even tapped it with a 1/4-20 but you get like 1 thread. Also 3/16" pop rivets work great to attach it to you chassis or to use the material as a gusset.
The only down side to the material is that once you cut it the edges are really sharp because of all the holes. Also I would not recommend that you try to make a lot of bends in it because it will eventually fatigue and break.
-Clinton-