See if you can find a local supplier:
http://www.thomasnet.com/nsearch.htm...0571819&loc=CT
Also search on "steel service center". Look in your local Yellow Pages as well. You should be able to locate a number of local suppliers. Then hit them up for a good discount or a sponsorship! I got a some freebies from a couple local metal suppliers.
If you don't have any luck, call a local welding supply company or a welding shop and ask for names. You might even find a recycling place that sells scrap material.
Here's one local supplier:
http://www.emjmetals.com/index.htm