A few thoughts:

I usually start most of my flight searches with Kayak.com. The site will search all airlines and booking engines for the best prices. It also has a flexible date search feature so you don't need to plug in each day separately, you can choose within a three day range for departures and arrivals. If you don't care about which airline you fly (for earning frequent flier miles) then price is you biggest consideration. Just stick with the big name carriers. Kayak will find the lowest fares and then point you to the website that is offering the fare. Once you find the route/fare that works for you I strongly recommend that when you book your plane tickets, do so at the airline's own website and not with one of the third-party websites (expedia, orbitz, travelocity, hotwire etc.) even if it is a bit more expensive. If there is a flight delay or a cancellation and you need to be re-booked (for whatever reason) having booked your ticket direct with the airline you are actually going to fly on will save you major headaches! In the case of irregular operations, airlines will re-accommodate the first class, business class and elite frequent flier members first and then those who booked with them directly. Those who booked with orbitz (for example) are often told to go and re-book with them which can be a royal pain in the backside.

As for flying in to one city and out of another (that's called an "open jaw"), that is a great way to go and often not any more expensive. Good idea in my opinion!

The other thought that comes to mind pertains to the timing. Personally, I would rather fly over and get the work portion of the trip out of the way and then have the remaining time be dedicated for fun. Once the work stuff is out of the way, should you and your husband find that you want to change your itinerary as you go, you won't have the work obligation to factor into the equation. Just my two cents.

Have fun!