The standard car has a heat exchanger around the filter housing, but techs tell me this is more to bring the oil upto temp quicker rather than offer any cooling effect.
As for the catch tank you only need to consider one should you vent the breathers to atmosphere, in itself I see little point in doing this. I have breathers on my engine but just because the ITB setup doesn't allow for fume recirculation. On road use the breather never fouled with oil but at snetterton it got very damp and dripped oil. I'm currently fitting a catch tank to combat this myself.
As for an oil cooler I'd suggest you spend more on a high quality oil that can handle more heat rather than a cooler. Motul 300v can operate upto 120 degrees reliably. With my oil cooler ( 16 row ) I run around the 95 degree mark on a fast track.