These are technically called Highway screeds. I have two, 16' x 4" screeds and one 20' x 5" screed. They come with seven, 6' poles, all the braces and stabilizers. They are made by Cleform and are sold through Whitecap.
I will post pics as soon as I get home. Here is my ebay link.
http://cgi.ebay.com/Concrete-Screeds...hZ011QQcategor yZ56964QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
make me a reasonable offer and come get these things, PLEASE