I've decided to finally finish my rack so my cats quit using what I have as their own personal jungle gym. I have an opening that is 57 3/4" tall (33 RU). A google search came up with this place: and they have exactly the length I need for $112. It says it comes with 4 rails though (http://www.starcase.com/detail.aspx?ID=1008) (top maybe?) Seems kind of expensive though. I saw this link somewhere (http://www.milestek.com/shop/product.asp?id=50%2070536&cid=&kwd=&l=&p=)...I Could get the 45 space rails and cut them down for a lot less money.

any other suggestions on where to get the rails?

http://www.crawlinvette.com/home/basement/slides/DSCF3502.JPG

Yes,
I've used these guys for 20 years: here (http://www.markertek.com/SearchProdList.asp?sort=prod&off=0&skuonly=0&search=rails&pagesize=20)

I cut some 70"+ rails that I got form the dumpster at work down with a reciprocating saw. Worked well. :)

Try this link SmartHome (http://www.smarthome.com/8732r45.html) for a 45 Space (78.75-In) Rack Rail (Pair)