Yes Botswana is an option as somebody mentioned. I will speak to the embassy positions only here. For the embassy positions you'll still have a day job. Attache as several mentioned, but not always. One of the others is in the office of security cooperation, under DSCA, where you'll work Foreign Military Sales, International Military Education and Training, etc.
You will likely fly with Army or Navy guys in addition to AF. You won't get as many hours as a major mobility MWS.
To answer a few questions above, and some things I think are important, it's not the type of situation you'd want to bring an EFM family, and joint spouse assignments most likely won't work. Embassies are different, but many have very few military members. Some wives complain enough at regular bases, so if yours is prone to that, avoid. It's a downer to have a small community and a couple wives who complain about being homesick or stressed all the time. On the other hand if you're adventurous and outgoing and like to party there's a good network. But if you do a little research and ask yourself if it makes sense, it will probably be just fine. If you have kids check out the school situation, many mil people happily have kids in these situations. Obvi many of the embassy people have kids and they do fine. There are international schools, but these vary in quality by location and age. There's some perks like FEML plane tickets, US and Host Nation holidays off (if you aren't flying), housing and bills provided but you won't get the BAH. Usually no Tax free. In many places you can have a full time or live-in house keeper and gardner for a great value, which is awesome. You may have a rater from another service for instance. You may have a very small pool of aircrew to share the plane, so good luck, hope you get along.
The assignment can be a great experience, but depending on your job and location it may not be as good for rank progression as other more traditional options. But that varies by your time away from big blue, and varies by which promotion board you're looking at. For those that understand and welcome that fact going in the assignment can be an incredibly enjoyable time, a great break from big blue, a look into Dept of State/Embassy life, and immersion in a foreign culture. It can also motivate you to return to a regular AF assignment.
It may be an option as a second assignment, but I think 3rd is more common for the embassy gigs. Tour length also varies, but I've seen 1 year unaccompanied or 2 year accompanied. You may be able to extend either of those for a year. You can't take your spouse everywhere, but when you do take your spouse they may have the option to work. The DOS has a system similar to GS (but different incase your spouse is looking to combine time) where family members have some options to work at the embassy. This can range from part or full time Community Liaison Officer work, to other full time jobs around the embassy.
Hope that's helpful. I definitely recommend it to those that think it's a fit. Good luck!