Well depends the reason for the wires to be straight is so that they cut a certain size cube. Once you start pulling it would probably self align because the resistance of the curd would pull it to it's furthers poin from the frame and equalizing the distance. Should work fine. Actually to get enough tension so it stays relatively straight doesn't take as much forch as you would think.
If you have a nice shop vice all you would have to do is get 1/2" x 1/8" Stainless steel flat bar, here it's $16 for 12', so you probably should just buy an entire stick. Then mark your first bend point, put it in the vice tight and hit with a hammer. That's how I did mine. I did weld it shut, but it you have a propane torch for sweatin copper you do that if you buy the correct flux. It's an aicd base made by Harris. Or just bend the two ends where they meet drill a hole and bolt it shut with a SS screw and nut. Then go to your local welding shop, not store but an acutal welder, and ask for like 20' of .023" Mig welding wire or buy a small spool at the welding supply store and start it off with a wrap and a loose twist, a hard tight twist made with a pair of pliers would break the wire, it's kind of brittle. So twist with your hands then use pliers to pull it taught as you wrap it around the frame. As it goes around each side just wrap it once and so on.