I believe he has a DOHC and will use SOHC pistons for 11.1:1 compression ratio in his DOHC.
Porting and polishing is great, until you take too much metal off the head. Then you have warping and overheating issues. When I got my head done, I requested a port-matching and polishing, with a light job on the head itself. Chris May's car (2 motors I believe), a friend Jeff's KA-T in Conneticutt, and a couple others have blamed motors on the headwork.
What are the specs on Nismo cams? I know JWT is up there, and regrinds from PDM are really lumpy but make power up top. You'll need some machine work on the rotating assembly as well as crank work. High revving KA's don't seem to last long, and large cams won't making daily driving feasible. If you really want, look at rebello stuff and see if you can find any specs on their motors. They made 280whp NA KAs for race.
-Jeff