I don't think there are any MK6 r/c bodies out yet, most are electric, I doubt you'll find a nitro kit to purchase. MK5 will be a lot easier, Tamiya has at least one kit.
It's not a MK6 or nitro, but if you're looking for something fairly realistic I really like the ABC Hobby stuff. I built one of their Sunny Coupe mini 1/10 kits a couple of years ago. They make almost everything you need, chassis, body, light buckets, wheels, and accessories (license plate, mirrors, wipers)
Only down side is everything is proprietary, so unless you have a local hobby store that carries the brand, you'll have to order
everything online.
http://abchobby.com/productimg/genz/shots/sunnycoupe/index.htm