You might not be able to buy exactly what you want from 440Source. If not then look for a stroker kit from a different supplier. 440Source uses ICON pistons so you might have to find a kit made with Diamond, JE, SRP, Wiseco, etc. pistons. There are lots and lots of choices out there.
Don't use steel shim gaskets with aluminum heads but you can use Cometic gaskets. Cometic gaskets are available in lots of bore sizes and gasket thickness. Look at their website or catalog.
