You need to make your quench clearance between .025 and .030 and you will have greater detonation control and less octane demand with 10.5:1 compression than you would if your total quench was .060 and 8:1 compression.
You can have the perfect cylinder head and it is still completely null and void without the right cam as the cam is the cylinder head's link to the engine.
You need to decide how you will drive the car and at what RPM the engine is going to spend 99% of it's at. THEN you choose a set of heads.
The rod bolts are the single most critical bolts in the whole engine. For the effort and cost, you should just buy a set of Scat I Beam 6 inch rods over re-sizing a set of stock junk rods. KB part number 260 is a good budget piston for that rod. Or if you are looking for a premium piece, call Diamond. If you are looking to make power in a daily driver at those sort of RPM levels associated with a daily driver, then for the money( not withstanding the fact that AFR's are the nicest off the shelf conventional bolt on heads that money can buy), you can't TOUCH a set of factory stock Vortec heads for an idle to 6500 RPM 350 with 6 inch rods. The longer rods are also going to reduce the cam requirements it will take to get the numbers you want.
Email me and I will put an engine, Carb, Cam, etc together for you if you are interested in any of those items by them self or complete. I'll also give you a 100% guarantee.
Camshaft designer/manufacturer, full competition race engine builder, carb blueprinting.