PWR radiator cant go wrong.
Im not a fan of the japanese headertank setups, I do my own headers but just make you beed the top of the radiator, high points of the head and have a main filler on it.
Ducting has been said before, do it right and most importantly try to get fresh air over the intercooler and to the radiator.
You can do something very similar to what I posted above on the GTR.
I dont like mounting oil coolers inbetween radiators and intercoolers if its possible to mount them elsewhere. If you must put it there then I always run a dedicated duct for the oil cooler so its radiated heat cant dispurse into the air between the cooler and radiator. Have a rearward couling that forces the air out under the radiator from behind the oil cooler. ( i think that makes sence?)
If its track only get rid of the fan all together, seriously its unessisary if you have the cooling system set up properly for a track only car.
Undertrays etc just do your reasearch I dont feel they are important as the radiator ducting but they certainly have a place.
Buy an electric heated screen for window demisting. They work great but are pricey.