We use Weldon high temp pumps for our differential cooling system. The model 9200 is what you want along with a cooler from Summit or Jegs or.....
http://www.weldonracing.com/product/..._Oil_Pump.html
On sale here;
http://www.srmotorsports.com/Weldon_Fuel_Pumps.html
Cooler with fan here;
http://www.jegs.com/p/Perma-Cool/744433/10002/-1