What would you guys think about making it 3 pieces and ditching the heat sink portion.. Basically there would be the base, the front motor mount plate and then the rear support. It would screw together through the base.

This would reduce costs quite a bit because I could just laser cut it or waterjet it instead of taking up tons of mill time. After the cutting there would just be a few holes to drill and tap which I could do by hand, or make a tool (If the demand is there) to do multiple parts at once in the mill :)