Everyone above has given you great advice about what to do and what you may come across during your search. I wanted to wish you good luck on your search, because the more you limits you put on yourselves, the harder it will be. I'm not saying those limits are right or wrong, I'm just stating that the more restrictions you put on your list, the harder it will be to get that right woman to be part of your play. Just like house hunting, if you require 3000 sq ft., a negative edge pool, 5 bedrooms, 5 bathrooms, an elevator, a bath suite for each bedroom, home movie theater, has to be by the beach with no neighbors in the back, $300k budget, etc. etc. etc. then the search will be long and you might have to be more flexible about your list items if you want your fantasy to become more than just that.
But most important, you two need to talk about every step of the way--who, what, where, when, why of everything. Make sure you both are honest and listening to each other. Continue to read articles and threads on swinging and see if this is for the two of you.