I'm not an expert, but I think your mindset for entering into Aikido is excellent. The key thing is not to let your expectations become too great, because if you do it is likely they will be unmet. Usually those who stick with Aikido are those that have little expectation beyond the basics of the art (harmony, balance, conflict resolution). So, yes, I think your mindset is great.
I don't live in Raleigh, but if this is the place, run out of White Tiger, that you are thinking of attending:http://raleighaikido.com/
Then it seems legitimate. The only thing that kind of bothers me is the one year contract thing, but other than that their rates are reasonable.
However, the one thing I'd like to point out is Aikido can be taught in very different ways. I would strongly suggest you visit all the dojos in your area before deciding on one in particular.
This one here looks particularly interesting, as they also teach the arts of Iaido and Jodo, both of which are beneficial to Aikido:http://www.choshinkan.com/
The students of Toyoda Sensei are known to have pretty effective Aikido in general, so I wouldn't pass that dojo over if it is close by enough to get to.
Not saying the first dojo isn't good. Just that I would check out them both and see how well they fit you and your wife.