I have heard of a place in Minnesota that does rechroming and I cannot come up with a name off hand (something like Weststar or Northstar). An automotive parts company nearby named Keystone gets their bumpers rechromed there and I have never seen better quality yet. They charge $275 for straightening and rechroming, and the chrome is lifetime warranted.
I can tell you from first hand experience not to use the Bumper Boyz. I gave them a mint core rear bumper (light rust on the back and no dents) for my 69 Chevelle and what I got back was one that had no less than 2000 hits from the back to straighten it. I returned it and got one that was slightly better, but the mint one I gave them was long gone. When I turned in the nice original core, they (one of the owners and an employee) swore that they would engrave my name and invoice number on back of the bumper and I would be guaranteed of getting the original one back. NOT TRUE. Neither of the ones sent to me had a name or invoice number on them. It is too bad because they do nice chroming, but never trust them. After going round and round with them and getting nowhere, I feel this warning is warranted.
My final word of advice is to take your bumper to someone you know and trust and to get some sort of guarantee on the work. Make sure you pay with a credit card so you can dispute the payment if you get a raw deal. Hope this doesn't scare you, but be cautious. Good Luck.