Boy maybe I'm lucky. My recipe. Research what works for your desired combo. Send the pistons to the machine shop. Have it bored and honed to fit. Check line hone. Repair as nec. Deck as necessary. Make sure pistons, rods crank and cam clear each other. Check bearing clearance and adjust. Have the heads done by a reputable head guy. Check P to V. Trial fit valve train. Order correct push rods. Notch pistons as required. Balance assy. Assemble. If you can't or don't want to learn these steps and purchase the tools to do it. Then spend the $ and wait the time for a big name shop. Correctly done the result will be the same. Just a different time line and $.
Doug