Don't... what you have works and is reliable. Raced and raced and raced on standard head gaskets. Good flat surfaces are more important IMHO.
The only attribute I can think of for Cometics is their resitsance to blowing out, and some good variability in setting thickness and hole size. But your SCR/DCR is set fine as it; tune it right and be happy.
BTW, the damper looks good. If it seated firmly when installing, and you got the 135 ft-lbs of torque on the snout bolt, then it sounds all right.
