I like the floor mounted ones with pull cylinders as:
http://www.apracing.com/info/product...F%3E_2351_2342
It should not be out of the question to fabricate your own version using AP's pull cylinders and trunnion balance bar. (AP do actually provide a download of full tech drawings for the unit!). The floor will have to be raised/overlaid by 2" (50mm) but as I have proved this is a distinct advantage for pedal control and comfort even with the standard pedals. If you are fabricating it then a modular approach could be employed retaining the cable clutch for a future substitution but the throttle pedal as well as the brake pedal would have to be changed to accommodate the raised floor. The resevoirs could be sited anywhere convenient.
Clive