I am a HUGE Priceline fan, but I wouldn't use them for a ticket to Orlando for the cruise unless I had all day the day before and wouldn't fly home until the day after arrival back into port. Yes, absolutely, you will get the airport you select, but you can not pick times at all. When you enter your date for travel, you are agreeing to travel anytime between 6 am and midnight, if memory serves me. There is no way you could take a chance on the flight time for same day arrivals and departures. I think you specify if you are willing to make more than one connection, and I don't think they will ticket more than a 2 hour layover. It is a GREAT solution to a family vacation of a couple of weeks when a day lost to travel doesn't matter, but if you booked for a weekend trip, you could conceivably get an 11 pm flight on Friday and a 6 am flight on Sunday....not much of a weekend.
Be careful with Hotwire. Sometimes deals do appear, but sometimes the Hotwire price is higher than if you booked directly with the hotel or car rental agency. I think Orbitz is a lot like Travelocity, except I think their website is ALWAYS slow and cumbersome.