pretty sure that extractors and cams for a 4k will need to be custom made.
as for the weber kits u can get them off ebay.
also if you like near freo you could try gibbos south street auto parts. and ask for rob.
he gets me most of my shit for 2tgs. be patient though hes flat out all the time.
tell them preston sent you for a lil discount.
cheers.