Based on the recommendation of RogerC I ordered the dual fan assembly from <UL TYPE=SQUARE>
www.ramchargers.com[/list]It just came in and it is a really nice unit and a heck of deal at $79.99. The fans motors have two speeds, it has a built in shroud and should fit the common 31x19 aftermarket GM style aluminum radiator pretty well.
I will let you know how it works once installed. A big thanks to RogerC for the heads-up!
Chris