Dragon makes a 'Final Production' King Tiger which includes the Transport Tracks its kit #6209
I like the Dragon Kits better. The Battle of the Bulge King Tiger is an excellent kit and you get the brass shells, PE parts and 5 figures at approx the same price as the Tamiya kit. I almost exclusively build Dragon Kits because you get more value for your $$. So if you want an early model King Tiger then thats what you want.
I also have the Dragon Porshe KT w/ Zimm and its also too an excellent it. No fit problems, no flash, PE metal detail parts, alum gun barrel, metal tow cables, you can't ask for more.