Andrew, the kinco drives are good. I have Nema 34 motors on them and they are fine. The only problem is that the drives generate alot of heat but a couple of cooling fans will take care of that.

Guys, thanks for info on cutter loading/feed speed. I willl have to play with it to get a feel for the right speed and loading. The step over and feed speed was what cut2d generated when I picked that cutter. They can be modified but I decided to go with the stock option as a first timer.
I do have plans for two spindle mounts but havent gotten round to them yet. I have ordered some of the single flute cutters off ebay so that could be a good test when they arrive.
Jonathan I am using USBCNC not Mach3. It has something called look ahead feed built in to it. I think this looks ahead of the block you are running and looks at the program to see what is coming up. It then tries to calculate the optimum speed for those upcomming blocks to keep the machine moving smoothly, well thats what I got out of reading the manual anyway!