my pistons domes are coated by swaintech....seens to keep hot spots down. Unless you do a bunch of tuning and timing/boost advances, there will be no gains from the coating.
Skirt coats don't bother....especially for 100 bucks
i'd stick with stock bore, why spend extra $ on a bore over....just run more timing or boost
Now these suggestions are for someone running a mild BT setup...if you're shooting for the sky, expect to throw all your money at it....but the majority of us here stay under 600bhp, which in today's terms is mild.