It looks like you *might* be able to use an AXIS HD-PTZ with one of the generic drivers?
The Full-HD could be surface mounted on a conduit base apparently?
http://www.axis.com/ca/en/products/axis-p5635-e
.. or the smaller 720p unit?
http://www.axis.com/ca/en/products/axis-m5014
Again, I'm only guessing at the moment. I haven't had the opportunity to try either. What I have tried out is the Axis M3007, which is pretty slick... but may not be suitable for your needs.
All the best!
Scott Olsen
Solutions Specialist
Bulletproof Solutions Inc.
Web: www.bulletproofsi.com