Also, depending on your credit score and your willingness to get more credit ( many folks are skittish about this because it requires a lot of discipline to stay on budget), both you and your husband can apply for cards with bonus miles to get a leg up on accumulating miles. I had my wife get the US Airways card separately for another 40,000 miles and am seriously considering having her get the AA card as well. If she does get the AA card, that will be 180,000 mile for getting the cards. The annual fees are around $89 per card.
Another method of getting miles is buying/sharing miles. I am US Airways Gold status and I get offers for additional miles every month or two. Sharing miles is cheapest. For example, I can share 50,000 miles with my wife and she gets 100,000 mile for a cost of about $530. She then shares miles with me and we end up with 100,000 miles for about $1,060. You can use those miles for a business class ticket to Europe (cost would be about $5000). If you buy miles during the bonus offer, 100k miles will run about $1,850. Again, you would pay this amount and use the miles for a business class ticket to Europe or even Asia. Depending on the airline/alliance, you may be able to get first class to Australia for 110,000 miles. Well worth it!