Wow those headers are beautiful, perfect shape, Love the twin catalytic converters, I'm sure with custom work that could be made to fit a beams engine. VVT-i is a design which (better than previous designs -- VVT, ACIS, TVIS) addresses the age old tradeoff between low rpm acceleration and high rpm horsepower, the tradeoff being that the engine draws in air most efficiently at a certain rpm depending on a number of factors (shape & size of intake & cams--which lift the valves, etc.) On an economical engine with low horsepower, then the engine generally breathes the best at a low rpm giving you good off the mark acceleration, on a high horsepower engine the low rpm acceleration generally suffers due to the valves/intake being too wide open for the lower rate of air that needs to be sucked in at that rpm resulting in lost air velocity, but in the high rpms acceleration picks up stronger and stronger instead where the economical engine's power would hit a plateau.
VVT-i does a fantastic job of giving you the best of both worlds by effectively altering the profile of the cams, the changeover happens a bit past middle of the total rev range.
The beams engine I think uses an air flow meter which means you'll need this silver thing in the picture here which says HKS on it with the filter attached to the end, thats the air flow meter adapter.

(Thanks to Google Image for that one)
Sometimes you get airflow meter adapters which bolt on with a plastic flange to the pod filter it comes with as a package, The one you see in the picture is the general 3" clamp type and the airflow meter adapter's end is the same as any other ram pipe, just clamp onto it