Any engine or trans oil cooler should have some form of temp control.
On a trans cooler, it is normally connected in series with the radiator. This works well, and does not need a t-stat and bypass since the engine coolant temp in the Winter keeps the trans from running too cool and building up sludge from condensation. If you use a engine oil cooler in any of the states North of FL, Tx, and S Cal, you need one with a thermostat and bypass, or you will build up sludge and acids in your oil in the Winter. I have used non thermostat controled oil coolers on my street/strip cycles, but used strap on covers on it during all the year, except the Summer. The oil needs to be above 180 in regularly use, or you will be causing problems.