Carl
I presume you mean a motorized focuser as autofocusers are quite different
You could get one of these to add on to the micro focus shaft, but do check with them if it'll suit your focuser
http://www.bintel.com.au/Accessories...oductview.aspx
Autofocusers from what I understand require ascom control and the software would measure fwhm and adjust till optimum.
The optec tcf does look very good, but I'm guessing is quite expensive as well
Cheers