How can I route the shower plumbing back into the wall?
That type of control valve is intended for the pipe to stay inside the shower enclosure.  Why not just run it up the wall to an elbow and then across the ceiling to another elbow for the showerhead?

Otherwise you would need a control intended for all the plumbing to be inside the wall like this:



There are a number of accessory finishes for the handle and trim.