With SS you always want to use the name of the hotel (not the zipcode), and yes, with LGB I get $35 first person, $9 each for additional guests. (although, interestingly, I'm getting the same LGB price even using the zipcode, so maybe they fixed that problem? or it might just be a computer cookie problem...oh, no, checked it with LAX and SNA, big differences for those airports!)
While looking at rental cars, be sure to price it out just keeping the car. On the other hand, Fairfield is now charging for parking. So maybe that's a bad idea. But since you might be new to rental cars due to your ages...one way rentals are generally VASTLY more expensive than a round trip. They just hate (or perhaps I should say they *love*, ka-ching!) suddenly getting a car on their lot that they felt they weren't supposed to have.
For going home, since it's just the two of you and you're younger, I'd take the red-eye. I enjoyed red-eyes in my 20s. Not so much anymore! The day's shot anyway; might as well get home early. And it cuts down a night of hotel cost. Then again, you have to be up and ready, leave your bags with the front desk, etc, if you don't have the room that night.