"scratching the surface"

[Ellis]

I can't see any benefits over electric power. The torque an electric motor provides is essential in all things robots, pretty much. Plus, unless I'm missing something, I see no way of getting a proper melty brain drive out of an engine. Also, clutches? Fuels? Exhausts? I'd stick to the proven!

edit: see you edited that post :P

You'll generally find ESCs cost more than motors, unless you're including gear reduction into those price figures.

There are hundreds of options to look into, brushless-wise. I have no idea about ESCs, though. In conventional tank-steering robots, whilst as Mario said, brushless motors are ready, speed controllers that are suitable are hard to find.

There are one or two brushed motor options. The larger Dewalt motors, such as these, for example, have been the drive behind powerful featherweights (even lightweights) for years.

edit: as for wheels, "Banebots" 98mm wheels are popular. They can be found on www.technobots.co.uk, though Banebots are actually an American company.

oh and yes, custom wheels are very possible. Again, videos on how we made ours are on the channel linked in my sig.