Hi - The way I've always staightened steel wire is to clamp one end of the required length in a vice and the other end in a drill chuck. Pull the wire tight and then start the drill at slow speed. Be very careful not to over do things as the wire will eventually snap and whiplash, so always use eye protection. I've never tried to staighten brass wire though so you will need to experiment! Good luck.
? It only comes in spools and I really need it straight. 
