http://www.racerpartswholesale.com/product/1546/Mocal_Differential_Cooler_Pump
I recommend that, I did a rear-mount turbo setup of a '94 Nissan sentra and used a tractor oil pump, when you're circulating hot oil you gotta be careful what pump you use, especially if your turbo is depending on it. I used a oil pump off a tractor, worked fine. And any oil cooler would work as a mini resevoir kinda, but it might be alot easier just to plumb it into your oil pan and a sandwhich adapter off from your oil filter. You just gotta make sure that the resevoir or cooler and pump you have will provide enough oil pressure for the turbo, which that Mocal should. If you're looking for a cheaper pump go to a tractor supply or some sort of heavy equipment shop and they should have tons of electric pumps that can handle it. B&M makes good oil coolers in all shapes and sizes..good place to start...Also, if its a separate oil system for the turbo, i'd highly recomend putting your own oil pressure gauge in the system somewhere.