Belts or Balls getting me Screwed up! Help I need advice Please.

[longy]

Hi everyone, I've had a play around with the design and changed the orientation round. It won't be a problem working over the side rails and as Jazz said it will make the machine stronger. Going to order the rails from china as I don't mind waiting a few weeks as I have lot of other things to do.

I would like your views on the ball screws to use ? so I can order these as well. I'm mainly going to be cutting and engraving wood and phenolic (laminate) and some plastics. Next will be the motors and drivers but not in a rush at the moment due to a lack of funds.

Your help will be much appreciated in getting the right ball screws.
TiA Mike