I'd defo go for a CAI closed one to keep the noise down reckon you'd get another 10bhp with good fuel too... So 260+BHP, I'd say that was pretty damn decent all things considered.
That 197 g/s wall which lasts for a few results could well be the restrictive oem air box.
I'm running stage 1, precat delete, panel filter and make 247bhp... Been looking into a quiet CAI myself... Might consider the stage2 if your tests go well.