Hey Jesse,
Initially I bought a panel filter from
www.ybfilters.co.uk. This filter is now in CougarBoy's car and it does pretty good.
I upgraded to a K&N AirCharger kit which is a pod instead, I bought mine from ebay, but ProfessorSabre sourced his from South Australia, a shop called CarToys
www.cartoys.com.au I think is their address. Get a proper kit rather than just bolting a pod on, otherwise your engine warning light will come on in your dash.
Depends what you want. For just better airflow, get the panel filter, it cost me about $100AUD from YB Filters and arrived in about a week or so. Autobarn Penrith offered one to me for $120AUD and it would've taken about 2 months to get it!
If you want the whole pod thing, and the induction noise, then the Air Charger kit is the way to go, but can cost upwards from about $350AUD to $500AUD.
Dan