Unless I misunderstood you, I think you mean to say the amount of dish in the piston...the CH of any piston is the measurement from the pin bore center to the crown of the piston (dome/dish notwithstanding).
And if you're looking to make a specific compression ratio, yes, you would do well to figure out what your chambers measure out to, what kind of head gaskets you will use, and then you can take the actual block deck height measurement into consideration to figure out which over-the-shelf pistons you want to purchase...unless of course you're wanting to go custom.