Hey Canadian, I just installed the Airaid spacer. You have to use the Dodge part number AA300-574. I got mine for $147 plus tax and it installs easily. I am not sure about performance or miledge gain but will keep you posted as it is the only mod so far. I don't think the air intakes are worth the $400 or so Canadian they cost, the tube is only 12 inches long.
'07 4.7L, QTII, duel power & butt cooker seats, remote start, class IV tow group, tow hooks, factory skid plates, Light Greystone..........Poweraid Throttle Body spacer, 6000K HID low beams & fogs, AVS Rain Guards, Flowmaster 40 muffler, Daystar 2" lift, Bridgestone Revo 2 31" x 10", Cobra CB, front sway bar disconnects
My Youtube: http://www.youtube.com/user/cnorrss