I don't know if you already know about these sites, but they have a lot of CNC conversion info.
Sieg X2 Mini-Mill (aka Harbor Freight 44991, Grizzly G8689, Micro-Mark 82573, Homier 3947, Cummins 7877)! Harbor Freight 8x12 and Sieg X2 Mini Mill, DRO, CNC Conversion Plans, Machining/Metalworking How-tos and Resources
Home Model Engine Machinist
The Hobby-Machinist.com - The Friendly Machinist ClubŪ