I am 6'4" and 230lbs and my -8 is extremely comfortable, in fact that is the reason we built an -8. I trained in a -7 with a guy who is 6' and 230lbs. and it was tight, but not uncomfortable. The -7 is more practical in the sense of baggage and person to person interaction in the cockpit. Both aircraft fly virtually the same, so I think the question becomes how often will you fly alone and if not, will your significant other fly behind you. Personally, I have never had someone who wanted to fly turn down a ride in the back of my -8. Hope that helps or maybe I should be a politician! Either way you end up with a great ride and you will find very creative ways to leave work and go fly your RV!!
Good Luck