I ran across these rails and picked up a pair. There are a few left if any of you are looking for stuff like this:
http://www.ebay.com/itm/321335524441
The travel is more than I need, but I will extend the two blocks further apart on the rails to decrease whatever play in the rails I encounter by as much as possible.
They are realy nice and good prices.
Maybe i will order also a set :D