Welcome to ecomodder.
Done !
http://www.amazon.com/s/ref=nb_sb_no...CCI+IWC202-15C
If you don't really want the chrome plating, these are cheaper :
http://www.amazon.com/CCI-IWC413-15S...sim_sbs_auto_6
Both designs look reasonably flat, with little surface area being opened up, so they'll be OK. Completely closed designs will work a tad better still, but you'll get most of the benefit.