For those of you near north Alabama, I saw a post on Craigslist offering large plastic barrels with lids for only $7.00. Looks like they'd work well for someone building a cyclone. See http://huntsville.craigslist.org/mat/1489125416.html (http://huntsville.craigslist.org/mat/1489125416.html). BTW - I built the 5-gal bucket version for my small shop and it's working great!
Nice deal on them. Too bad that's not Huntsville Texas...