I'm 6' and 240 and the mids are a little cramped for me, but it's not that bad. I just did 140 miles last Saturday and I wasn't to sore. I have forwards on the way! I will post back how they feel.
Most of the dealers have many new and used sportsters. Pick a nice day and go test riding. Try both mids and forwards and see what suits you and your wife. You will probably find yourself riding the sporty more than your other bike for short rides around town.
I am 6'1" 230ish and my 98 1200 custom feels perfect. However I have the forward controls and a customized stock seat so that helps but it is still a good fit.
I am 6-3 and when i had my sporty, I and forward controls, and a seat that was cut back about an inch. The long rides killed me but that bike was fun as hell.