look in a junk yard?

Look in the yellow pages for an industrial steel/ metal supply house. they'll have what you are looking for.

Cool, thanks everyone!!

if you want to make a box then you can buy some one inch black pipe from home depot or lowes. cut the threded ends off and bend them down and put a peice of ply wood inbetween the two pipes. cover the ply wood with polyurathane and make legs to stand it up, also put connecting blocks to each leg so that it holds up to the punchment

Sweet! Sounds good thanks!

Look under the 'free' section of Craigslist... usually some unique jibbable (if that's even a word lol) stuff on there that might contain some metal you could use on a rail.

Hollow Structural Sections (HSS) or "Tube Steel" comes in 4" 6" or 8" wide by 3-4" and how ever long. It can be bent by the supplier for rainbow sections. I once had a 50 foot rollercoaster made out of 8" tube steel. (too wide in my opinion)
http://www.shoptheblend.com/sb-team-snowboard/images/peekn_peak_wny.jpg

I tried the Craigslist comment, and it actually works. Within 2 minutes I found something that I could use. It was by no means perfect but it would hold me over until I found something better.

Great advice, thanks everyone!