Good place to buy Frame-connectors?

Go buy some 2"x3" 1/8" wall box tubing, either a piece 12' long or get 2 pieces 6' long and cut them to the exact length you need with a torch or better yet use a plasma cutter (does such a neater job). Also get a piece of flat 1/8" thick bar or plate 2" wide by roughly 10", or slightly more, long to make the end pieces that but up against the crossmember. It will cost you a fraction of what you'll pay to order them and you can make them fit exactly the way you want. Thats how I made mine, and since your welding them anyway it wont matter that there are not any bolt holes. I will try to snap some pics of mine and post them up for you later if I can. Got to get out to snap some pics of a valance for another member here anyway so I will try to do that yet tonight.