Peter
I have a fairly old JMI focuser that came off my 20". I think you could call it low profile, I will measure it's height tonight. It is only 1 speed and uses nylon grub screws to hold the EPs, but it certainly works just fine.
Here are photos of the focuser. As mentioned in PM it has a flat base and is 44mm from top to bottom when racked in fully. The plate in photos is the plat that is used for the collimation grub screws