There are plenty of them out there. However, if the rim is still in good condition overall, then I'd suggest taking it to a machine shop to see if they can straighten it. Many machine shops have the knowledge to pull it off (it isn't really very hard), and it will cost much less than a new rim.
I remember reading a 4WD article on which rims were the toughest. The testers took the tires off each rim to be tested, and drove a fullsize truck offroad on some gnarly surfaces to see which rim held up the best. Afterwards, they had the rims straightened at a local machine shop in southern California. Total cost for straightening was less than $40 each. That was just a few years ago, so I bet your rim shouldn't be more than $50 or so to straighten at a legit shop.
Camelman