Thanks, Joe. By the the way, thanks for posting all the info on the Hetzer. Not sure if that's the one for me (might be), but seeing it all laid out is very helpful.
Another option was some motors from the Robot Marketplace site. They have plenty of choices, but torque and motor rpm vary. about how rpm do the drive sprockets need to be turning to have a decently quick tank? Not trying to be the fastest tank on the battlefield, but don't want to be outrun by snails, either :)