Hmmmm
There's always different ways to skin a cat !!!
A Shoestring GPUSB adaptor would just connect to the guide port on the mount
http://www.store.shoestringastronomy.com/gpusb.htm
I assume your guide camera doesn't have a ST-4 port??
Re the EQ-Dir module this connects to the mount instead of the handcontroller and allows the mount to be controlled from your computer using say CdC and EQMod.
EQMod also allows you to select "pulse" guiding.