My new Ron Davis radiator arrived yesterday - he doesn't even like the idea of an integrated tranny cooler - so ordered mine without. I'm replacing the junk epoxied tanks unit (that would be the SECOND epoxied tank radiator gone bad!). You might want to just look at using the "along the frame" style finned dual pass oil cooler(s). You can use a large one or a combination of them to fit wherever you can find space.
I think these would help more on a track car than on a street car - as the track car is moving almost all the time (except that time you spend with the nose up against the wall --
) where a street car can spend a lot of time in stop and go traffic etc.
Just my .000000000000005 worth
PS - They always market this style as a transmission oil cooler - but I can't think of why they couldn't be used to cool engine oil - the pressures and temps would be about the same? and the ones I use are AN equipped.