Maybe try a sleep number bed, with two adjustments on them? That way, you can have it whatever firmness that you want, and he can do the same on his side?
And, I would really recommend a king sized bed too. We got one after we got married last spring, and slept in a full with Emma! That didn't work so well, because my husband is 6'3" and 215 lbs-not a lot of room for us girls! His feet also hung off the end, and it was really high for Emma to be jumping up and down from, so we got a king sized platform bed. It only takes one no-flip mattress-no box spring, so if you splurge on a new bed, it saves you a bit since you don't have to buy a box spring.
As far as separate rooms/beds go, I suppose it's whatever works for you. I haven't been married that long so I can't tell you one way or another on that. I personally wouldn't like it if my husband slept in another room-I feel "safer" and content knowing he's right there next to me, so I sleep better, and the dogs do too. I love waking up to him-even if he is snoring or drooling on my pillow
On nights when he's been up late, out late, or away on business, I don't sleep as well and neither do the dogs.