Any reason why you wouldn't go with K&N? You won't really gain much, if any. The stock intake is already a CAI, so I understand why you would like to keep it. For the amount the VX filters usually go by, over $350 (last time a looked a few weeks back) you could buy a long tube or replace the airbox. I was a little hesitant on using the K&N at first, but really, oil based filters are just as good as long as you know how to oil it properly. The VX also uses oil.
Mines VX Air Filter Set