Did you buy the pistons from Summit Racing and are they still in the box? Summit Racing will swap the pistons as long as they have not been installed on the rods. These are the pistons that are needed Keith Black/KB Pistons 9902HCKTM030 - Keith Black KB Performance Claimer Piston and Ring Kits - Overview - SummitRacing.com
There is no way to use the pistons that you have. They have hollow domes that cannot be machined down. I feel bad for you being in this situation but you should have came here before you ordered any parts. You are saying they recommended that camshaft K12-365-4 and the 1.6 rockers. With the pistons you have the compression is so high you would have to use reace gas (110 octane).