I see that you are from NJ. If you fly out of Newark, make sure you are getting a non-stop flight. Airline choices are few. We usually fly United, but we are always firm with our resort reservations; and I usually book our flights six to nine months out. Jet Blue also does non-stop to orlando. Spirit used to fly out of Atlantic City, but I don't think they do any more. If you are closer to the NYC airports, try them. If you are very northern NJ, Newburgh, NY airport used to have JetBlue flying direct to Orlando also. If you are western NJ, Allentown airport has Allegiant, but they only fly into Sanford now. However, if you are closer to Philly, you have alot more choices (including Southwest and great prices, but I don't think they fly direct, but I could be wrong). If in the Princeton/Trenton area, Mercer airport now has Frontier airlines; I think they fly once a day to Orlando. That can be dangerous, if there is a cancellation, you don't have much recourse.
United has many daily nonstop flights from Newark to Orlando and their prices can fluctuate more than twice a day. You also have to add in the expense of parking at the airport or car service in addition to renting a car in Orlando unless taking DME. If taking DME, then you are kind of stuck in Disney and don't have the freedom of going off property to eat or to load up on groceries (but you can always rent a taxi or rent an
Alamo car for the day from the Dolphin Resort or the Car Care center near MK).
We drove to Disney once from NJ. As much as I hate to fly, I really don't think I want to drive there again. However, if you are a family that is used to roadtripping, it probably isn't all that bad.
Anyway, getting back to your original question, I guess picking an airport in the flight searches first might be the way to go.
Good luck with your search and enjoy your trip.