Hello fellow adventurous newb,

I'm doing the same thing as you it seems (well it is a CNC forum).
I wish i had more input for you , to help you on your way.
I'm looking at purchasing Linear rails as i've used them before and the seem to give a better result (V Bearings on my Laser CNC work ok thou).

My input is i've searched and searched and think i've found a supplier of rails which don't cost the earth.
How much is the rack and pinion costing you??