air intakes

im either looking at an rs4 airbox which is pretty good or an after market one, i've never been a big fan of aftermarket ones generally and on previous non turbo cars i have ported the airbox with good results, but never tried on the turbo car as last one the box was good for that power
the 2.7t i'm planning to go 400hp+ bigger air flow on the twin turbo, whats normal for this power band for low capacity engine like v6 with upgrades on the intake, i know there are lots of debates on which is best for 1.8t, anything similar on 2.7t, doing some research on AW evo motorsports tends to let in more hot air and less effective, the abd kit is new looks robust but is essential an open in the engine bay induction filter which i am not keen on. bmc is very small feed and i'm not keen on it, boostmachine stage 1 which i saw people like on the cars it is available for and with twin feeds looks good to me.
I do like k&n filters although overal flow stays the same they have always responded much faster on last 3 NA cars i have had and last turbo car and this in stock setup, i would be keen with anything like k&n which has proven reliable as k&n has been so far for me. i have never had a maf failure also which i know is often brought up as an issue.

thanks in advance

oh yes i actually have one Rich, not used it yet, the unit is big, but the feed to the unit seems a little small when comparing to the boost machine dual feed