Those look like standard 3" cone filters to me. If you are going that route, make sure you're building some sort of cover/casing for them otherwise you'll just be hurting performance sucking in all that underhood hot air.

I was going to use something like this: http://item.mobileweb.ebay.com/viewi...id=20886992215
But decided the end cost was going to be close to the NW setup (when I got it on sale) and not near as clean looking .

And as far as attaching to the front. The NW setup uses a 3" silicone tube on the pass side and 2.5" silicone tube on the drivers side. You have to remove the plastic factory inserts to wedge them through. On the front side, I have the "devil horns" to help direct the air.