Radiator and Fan selection

Im in the process of hot rodding my inline 6 and was wondering if i could get some advice on what type of radiator and fan set up I should go with. Ive heard some people say to steer clear of aluminum radiators not sure why though?
 
Aluminum is very fashionable right now, but the real advantage is weight, not cooling, cooling is a function of design, not material. Plus, of course, it's easy to repair a brass radiator, if it comes to that. A three-row brass with the V8 shroud (the I6 shroud is unobtainium) and 6-blade thermal clutch fan is the way to go. Not a non-thermal, and not a flex fan.
 
That is the first time I have seen that aluminum does not cool as well. If you only compare metals Al is not as good. Where Al makes up for less heat transfer is that the tubes have more surface area.