I would go with a feiago 7l motor, and gear for around 35mph. That should be fine with your 10 cell 0amp esc combo.
Heres a few pics of mine. Motor mount is made of carbon fiber and works well. You could use al as well.
Battery tray is just an al angle with a piece of plexi riveted to it. I use verlcro straps to hold the battery in, around the length and top to bottom.
I moved the esc to a platform above the rear driveshaft. Was not too fond of it on top of the servo.
