In my experience, the Mocal Gear Pump http://www.improvedracing.com/oil-pumps-electric/electric-fluid-circulation-gear-pump-17-311-p-605.html is noticeably quieter than the Mocal Diaphram pump.
Paul
http://www.nobleford.com/search/new-shelby_gt350/tp-md3236/
Local to me. Was still on the lot on Saturday. No sure on how firm they are on pricing. Good Luck.