I don't think that an aluminum alloy wheel can be straightened. The type of reconditioning my buddy does is mostly cosmetic but can replace broken or missing chunks on the outside surface or wheel lip. He bought a franchise and travels to car dealers repairing the wheels right out of an 8 x 10 tow behind trailer.
Apparently, the Company has developed an proprietary two part aluminized epoxy that goes on like thin Bondo to fill holes, build-up missing parts of the lip, and clean up where the wheel weights are mounted. After it dries, it is sanded and/or shaped and reapplied if necessary. The Company also developed a proprietary paint called "machined aluminum" and looks damn close to freshly machined wheels. Other colors can be applied to the wheel at this point. The whole thing is clear coated and mounted back on the car after it'* dry.
He charges the dealers $150 per wheel mostly cause he'* dealing with Porche, Audi, Mercedes, etc. A small fraction of what a new wheel would be. He'* charging me quite less than that but I have to scuff up the paint on the crosslace wheels. No wonder he didn't want to do it cause it'* a huge pain in the keister.
I saw a couple of companies on the 'net that do the same thing. They are closer to the $150 per wheel mark though. If this is a mass produced, factory GM wheel, you might get one cheaper from a junk yard, this forum or Ebay.