Hi Alan,
The first choice would be what type of point motor, solenoid or slow motion like a Cobalt point motor. It would be better to glue the foam and then glue the point to the foam, then a point motor could be installed underneath or surface mount. If you are surface mounting you would need a spacer to bring the motor up to the height of the point.
The solenoid point motor is the cheapest but I prefer the slow motion point motor it looks so much better when switching.
I will be offering a new point motor package shortly, it uses servo motors and a digital controller. You can surface mount them and mount them under the point. Each controller can switch 12 servo motors. A DCC module will also be available which will have the capability to control up to 192 servo motors. The package will include the control module, 12 servo motors, 12 switches and LED's for route indication and a power supply. Price will work out around €14 per point.