I have both. In fact, I just purchased last year's Retina Macbook to replace the Macbook Air and really like it. There is a trade off between the two machines and only you can decide what makes more sense to you. I decided to switch to the Macbook because I wanted a better screen and more compact size.
If you opt for the Macbook Air, you will get a more powerful machine. You'll also have a decent selection of ports, familiar keyboard and the traditional trackpad. You will also have a lower resolution screen with lower contrast. On the other hand it will be slightly larger (on the 13" model). It will be slightly heavier and more bulky. It's a fantastic machine, but somewhat dated in terms of the screen and the overall design.
If you opt for the Macbook, you'll get a much smaller form factor with the new keyboard (some people don't like the way it feels, I personally love it) and the new trackpad, which I also think is improved. You'll get a gorgeous Retina display. You'll also be able to choose the color of your machine from the four available. The trade off is that you'll get less performance. Sufficient, but nonetheless less. And you'll get just one port and will either have to live wirelessly as much as possible or get an adaptors.
So, I guess it's not as easy as saying that one is basic and one is a step up. Each offers something the other doesn't. Ultimately, it's really about what features are more important to you. You mentioned taking it on trips. In such case, the Macbook is much more compact and may be a better choice. It will meet all your needs, including lite photo editing. If your husband needs more computing muscle to work with Photoshop or Lightroom, Macbook Air may be a better choice because of the more powerful GPU and overall better performance. Both are great machines - can't go wrong with either one
Good luck!