As we all know that all rails at resorts are made out of piping, but if you aren't very good with metal(welding), then you can use PVC. There are two kinds at our local hardwear store, a gray cheaper version and the traditional white heavy duty kind. For boxes, the most asked question is "What is the stuff you use to slide on it?" Well its something called Puckboard. We have all seen it on the side of hockey rinks. I have found a website that sells it in 50' rolls for $25-$35.
Hopefully i was a help +++++Karma plz!