Wrong pistons

Seems like a ton of expense when the gasket will solve the issue. Talk to your machinist. He should be helping defer the cost of fixing the issue he created. I would not go solid roller, or hydraulic roller. I'd get the right pistons, have the shop credit you the full amount for the pistons they got wrong, and then balanced, you pay to have it rebalanced, and stick to plan. But that's me.