I've used JWL's idea before and it works great. The black poly pipe can be picked up at any home improvement store and there are even double ended connectors availible so you can stick the ends together.
EMT will work pretty well also. you can bend it easily with a conduit bender or build your own table top pipe/tube bender. I'll draw a picture of one I built just for futre reference, it may not come in handy on this project but you never know what the future holds.