Here is a couple Battersea, I am also interested in the Ramair filter, I agree with your thinking with the velocity stack in the inlet tract so I modified my standard plenum as Barbagris did but used a panel filter instead of foam, but I wanted abit more air in there over the filter.
It is still work in progress as I am still sussing out the mounts, sealing rubber etc, but I wanted to see how it looked, its the first one out of the mold and is in gelcoat. If it all works out carbon fiber option down the track is a possibility.