I've been on a 42' cat, and with hydraulics, auto pilot, and all the bells and whistles, it is WAY more boat than I would ever want. Even if cost wasn't an issue. Finding places to dock a much smaller boat is difficult, much less than that monstrosity. You could easily get away with something in the 35' range for 2 people. All the money you save wouldn't have you worrying about what repairs need to be made. Cats have a lot of room down below, and 2 people will use the other 2 to 3 berths as storage and nothing more. No sense in loading up the boat with that much dead weight. Doesn't do a lot for the sailing characteristics of the boat.
The people who have been around the world in boats that are sub 30' in length were sailors. Not perma-vacationers. No reason why you can't incorporate both into your cruising, but take the comments above to heart. I'm 6' and 175, and work out 3-4 times a week. I have a spot on a competitive boat I race on every weekend. I would still not want to grind in a headsail in a blow of a boat 40+ feet. For you safety and that of the boat, make sure that you, and your SO is up to the physical demands of cruising a boat that size. When the wind hits gale force in the ocean, can you trust your crew with your life? B/c honestly, that's all you've got.
In case I didn't make it clear, I think 40+ feet is a huge boat to handle when crossing oceans. I personally wouldn't feel all that great about busting through a storm with a person that was 120# and struggles to carry a gallon of milk up a flight of stairs. I don't mean to piss in your cornflakes, but just something to ponder. I must say, I'm a little jealous.
