You can book LTT, Crystal Palace, Tony's and the Castle on party nights BUT they usually let you book LTT when you buy your tickets, well before the 90 day mark. If you don't book LTT when you buy your tickets, you will have a problem getting a PS later on. They will NOT require a CC deposit.
The other 3 restaurants open up at 90 days and also fill up fast.
Then you can also book a monorail resort restaurant but I'd probably book them early and get to the party early because for the last 2 to 3 years they've let party goers in after 4:00p whether you have a PS or not with just your party ticket. When the park closes at 6:00p, they herd all party goers to either Fantasyland or Tomorrowland (they can tell you are a party goer by your wristband). You can get quite a bit done before the party officially starts at 7:00p.
I usually book a MK restaurant for about 5:00p or 5:30p so I'm done before the party starts and then I get in a photo line before they get long and then before you know it, its 7:00p.
Enjoy!