List of some companies that purchase parts
and components for linear motion:

http://www.linearslides.net/
http://www.linearmotion.skf.com/

SKF Cataloges and CAD files: http://www.rtgilman.com/handb/handframes.html


Liner round guides (see 1st pic):
http://www.linearguides.com/sections/products/products_main.asp?PC=5020300&L=False&IT=&GI=1