To me, most of the fun and satisfaction of running a brushless conversion is from making it yourself. If I could have walked into a store and bought one prebuilt, it probably wouldn't have as much appeal to me.

Anyway, if working metal seems like it might be difficult, you might want to try working with carbon fiber. It is strong, light, and easy to work with common power tools. Just make sure that you take the proper precautions, so that the dust doesn't wind up in your eyes or lungs.

Although I'm using 7075 1/4" thick aluminum for my mounts now, I started using 3/16" thick 6061. It's plenty strong and very to work for a metal. I get mine from onlinemetals. Their prices aren't the lowest, but you can order cut pieces and it save some time. I think the last ones I got were 2 and 1/4" by 3". All I had to do was pop some holes for the diff and motor and do some drilling and tapping to mount it all up.