i recently got some mgwltd interior peices from a friend selling his car. I got the ac knobs light knob and door locks for 40 bucks, if you check their prices you will see how good of a deal i got lol, but www.mgwltd.com is the best for interior parts definatly pay the extra.
also get the bullit bezel IF you stay with brushed aluminum, if you go chrome steeda has a bezel that is shinny.
With carbon fiber, you have different options. You have the overlay kit, new interior panels, shift knobs, ebrake handles. Anything you can think of. Retailer :: www.cal-mustang.com
Bushed aluminum you can find at alot of Mustang retailers for cheap and anything you can remove on the interior (like door handles, A/C knobs), they probally have a billet replacement. Retailer ::www.uprproducts.com www.mgwltd.com
Chrome you have to search for a little more but it is out there. Retailer ::www.mgwltd.com
With colored keyed, you can either spray paint it or run down to the local paint shop and have them match and clear your panels for you.