If you do a lot of towing than yes a cooler is definitely better, heat is one of the biggest killers of transmissions.
PWR coolers are pretty good, any transmission shop should be able to supply and fit it for you. I had mine fitted by a mob at Stafford, glad I got someone else to fit it, those threaded lines just behind the radiator are bloody tight.
-Democracy must be something more than two wolves and a sheep voting on what to have for dinner.
James Bovard, Civil Libertarian (1994)
-Giving money and power to government is like giving whiskey and car keys to teenage boys.
P.J. O'Rourke, Civil Libertarian
-Government's view of the economy could be summed up in a few short Phrases: If it moves, tax it. If it keeps moving, regulate it. And if it stops moving, subsidize it.
Ronald Reagan (1986)