I'm definitely in need of an oil cooler -- 45 min of highway driving in Sunday's 90-degree temps had the needle at 250 degrees; can't imagine what 20 min on a track would do! -- and the Z1 Motorsports site does a great job of explaining the difference between all of the available options except one: what's the difference between a Mocal core and a Setrab core (other than $45?).
Please keep in mind that I know nothing about mechanics.