I would go with the WMD20 if it was me. Nice big table. It appears to be a G0704 clone. Probably all made by the same people.
I'm not sure the controller board will make a difference. Mach 4 is installed, and I really like the Mach 4 software.
The learning curve is a bit higher for it than some, but it will do anything and everything you would ever want to do.