Those KDWS are supposed to be really sticky and very high quality. The Khumo's are cheaper and they supposedly perform very well. I guess it might depend on how you plan to drive it, how much you want to spend, and what's important to you.
I have the Ford Bullit rims with the stock Gatorback tires - 245's at all four corners. They grip more than enough for the rides I take on the street. A 275 or even a 295 in back wouldn't add that much more traction, but it would look better. The gatorbacks have big voids in the tread design and they grab stones pretty easily. That's one aspect of a new tire I would consider important. Keep the stones from damaging your fenders and run a tighter tread design.
I have the Ford Bullit rims with the stock Gatorback tires - 245's at all four corners. They grip more than enough for the rides I take on the street. A 275 or even a 295 in back wouldn't add that much more traction, but it would look better. The gatorbacks have big voids in the tread design and they grab stones pretty easily. That's one aspect of a new tire I would consider important. Keep the stones from damaging your fenders and run a tighter tread design.