After seeing the horrid prices that BWC and Hepco charge for their rollers and rails, we went the home-made route...
First we did hardened wheels:
http://www.mechmate.com/Forum/messages/11/594.html
those wheels ran on rails made by a milling machine:
http://www.mechmate.com/Forum/messages/11/1932.html
This weekend I grabbed an angle grinder:
That picture was just the start, here are more pics showing the use of the grinder to get the bevels as well:
http://www.mechmate.com/Forum/messages/11/3790.html
It actually turned out fairly good - definitely good enough for a big board cutting router.