Are you sailing the Kombat with a single back strap and wave fin? Then I think you'll find the Kode 80 as fast. But if you use the added drive of double rear straps to help you go fast (and power a faster fin) then it will be a difficult match for the Kode 80.
At your weigh tthough, I think you will overall find the Kode 80 with its narrow tail easier to use, particularly with the smaller sail. I think it will be a great partner to the Futura 101.
The Kombat 79 is a very nice board too though, so no need to change just for the sake of changing.