Okay, but he's got the length, and at least partially, the weight issue covered. He did say he was moving up from a 30 footer, to at least 38 feet. Skip the lightweights. They respond more abruptly to sea and wind influences. Do not get a boat with an emphasis on flat-bottomed hull for downwind planing...it'll pound you. Look for a bow with a fine water entry, not a blunt bow. Generous beam makes for a roomy cabin, but don't take it at the exclusion of displacement. As discussed, heavy boats go through the water, they're less likely to get tossed about. In that comparison, it's a lot like a big old car vs the econo-boxes. The big car cruises like on a cloud, the lightweights get knocked around by the clouds.
If possible, arrange for some demo cruises. Nothing like actually feeling the boat in action.