Thanks for the information Chris! I was thinking of linear bearing blocks too after seeing it in Sly's build. Sly used VXB, which looks like a good choice.
Right now I'm trying to contact VXB in regards to some measurements for the 12mm bearing blocks because the Rhino model I built from the listed measurements looks like a flattened version of the actual bearing block. If I'm reading the measurements on that page correctly, the block should be 28mm tall and 42mm wide. Thus the height should be 2/3 of the width but the photos don't convey those proportions.

I'm emailing VXB about the dimensions and hoping to have a reply soon. Hopefully I did something stupid and that the listed dimensions are right (instead of me being right and being therefore unable to trust any of the measurements given on the site).
On a tangent, I am currently planning on making a highly modified LIL CNC. I'd like to include stepper motor dampers to increase IPM, an Arduino replacement for serial ports, a dust shoe, a cyclone dust trap.
In addition I'm planning on switching out the timing belts for leadscrews or racks & pinion. I feel like I'd end up screwing up the timing belts by tightening them to different tensions. I will update you on design modifications as I make them.