[Bermudahigh]

Most any catamaran will pound in certain sea states.
If you're looking to eliminate pounding, buy a monomoran.
I dont have rules of measurement that I can help you with but common sense should prevail. If the bridge deck clearance looks low, its going to pound more that one that does not look low.
Galley down works for us. Its open and inclusive of folks working in the galley with those living in the saloon. When I was chartering catamarans for vacation sailing, I prefered galley up. Living aboard, galley up is a deal breaker. I dont want to cook in my living room. We comfortably seat 6. 8 is a push, but doable for dinner.