What class is your plan???
Engines do not know whos name is on the valve covers
big swing between .040 and .100 for head gaskets that manifold sealing can be an issue, stick with one size and build with that (I prefer .063 copper)
you still have to put fuel in the hat anyway and I dont see any real gain by running port nozzles, It just complicates things (at the level we run)
My preferance is around 10.2 to .5 , but thats just me.
Your questions should be directed towards who will be making your pistons and will need to supply them with the block deck hight and cylinder head volume along with valve dia and cam lift in order to create a piston that will work for you--- without that info-- good luck
as towards coatings, I do see that it helps when running nitro. but they still burn them up, but no bennifit when alc is the fuel, If you do have problems, its not the pistons fault and coatings will not help
Berri Meza @ TRAUM Racing Pistons 310 259 5299 Head piston designer for ARIAS pistons before they closed shop and sold to CP You will talk to him direct