four major areas that will require some significant expenditures and are good for a little research; travel, lodging, food and tickets.
Tickets - if you're going for that amount of time an annual pass is your best option - at least for one of you. You could by a six day and seven day base ticket for about $20 less than an AP. Of course adding park hoppers to even one of those tickets makes the cost higher than the AP. I think that park hopping makes planning your touring so much easier that I wouldn't hesitate adding the few bucks per ticket.
You asked about the no expiration option. We do normally get this but we use our tickets over multiple years. I don't know if we will do it again though. Apparently people have actually been using the option as Disney has the raised the cost of this option faster than other options recently. We did add ten days of water park entries on this last set. This isn't a good option for you. A ten day pass with no expiration costs almost as much as an AP and the six day and seven tickets purchased separately.
Also APs come with some discounts
http://allears.net/pl/discounts.htm
Sign up for mousesavers.com newsletter. They have a link in the newsletters that provides a small discount for
Undercover Tourist tickets. We've used them the last two times and have had no issues. The savings from the link is not great but there is very little effort required.
Travel - Look early and monitor prices. There are websites out there that will monitor your flights for changes in cost. Some even have the fees for changing tickets built into their logic and won't alert you until the change is enough to offset the fee.
Lodging - there are places right outside the park that are cheaper to stay at. I prefer to stay at a Disney property for the convenience. Of course there are different levels of lodging. We have settled on a moderate - POFQ - as our normal resort. It seems to fit our needs and provides the best value to us.
When you go is very important. Next year resort rates drop (Value and Moderate) after 4/11 until early June and after 8/15. If you can work your dates around those you can save some money. The August rate change is larger than the April one. Also weekend nights cost more than weekday nights. There are sometimes AP discounts for room only or packages. The last couple of years the room ony discounts were announced in Feb for the April period and in June for the August period.
http://www.mousesavers.com/roomrates2010.html
Food - other than lodging an area where you can have wide variety of expenditures. There are practical ways to keep food costs down. We usually snack in the morning - maybe some pastry from the resort food court - and have a couple of meals. TS breakfasts are cheaper than lunch or dinner. Timing your meal later in the breakfast or lunch service can help save money. There are many ways to save - or blow - money with dining at Disney.