I got my tubes and K&N's from PartsRack (back when Vargus was taking orders
), and I've been totally satisfied with the quality, etc. However, I think the K&N's are a little thicker than the stock filters, so to prevent your airbox clips from popping off at an inopportune time, you might want to drill small holes in the corner of the airbox closure and zip tie it shut to relieve some of the pressure on the clips.
Whatever you do, I would not recommend shelling out the $200 or so to get the "official" Mopar smooth tubes - rip off.