I called a few companies that rebuild water pumps. This place REALLY new their stuff and more importantly, new the challenge we have with Pontiacs and the impeller. Its like he explained this thread to me all over again.
http://www.fdrbp.com/
$95 plus shipping back to you. Takes 3 - 5 days.
He also mentioned that the impeller breaks from time to time. The have exact replacement impellers.
Im going this route and I know Ill have a good pump.