If you want to spend the coin keeping 6 throttles is better for the street so the Nismo plenum would be best.
A friend of mine made 1300hp with one of those KU Engineering plenums which is single entry. Not very 'street' friendly at that power level though.
Intercoolers basically comes down to what you want to spend. Koyo Rads are well proven items too.
Also curious as to what hot side you intend to make the power with?