If it's in your budget, Victoria and Alberts is always my favourite. California Grill is a pretty awesome 2nd choice if you can time your dinner to watch the fireworks.
I would consider Cali Grill. The food is good and the view is stunning. They will whisk you up in a private elevator which adds to the evening!
You may also want to consider a restaurant in the EP area followed by a stroll around the Boardwalk. If you aren't on the dining plan, consider Il Mulino, Shula's or bluezoo at Swan/Dolphin. If you are on the dining plan, take a look at Yachtsman and Flying Fish.
Narcoossee's at the Grand Floridian! Time it out with the Magic Kingdom fireworks - you can view them right from the restaurant. Their best dish is the steamed lobster!
My DH and I recently tried the Boathouse at Disney Springs and really enjoyed that, too. We loved the crab stuffed lobster! It's fun to stroll around Disney Springs and do some shopping. They have lots of musicians all over at night - great atmosphere. For dessert, go to the Ganachery which is very close to the Boathouse for the best s'more of your life - super gourmet and indulgent.
I also agree with an above poster about Brunch at the Top at California Grill in the Contemporary. It is a delicious and luxurious buffet, but you can also get made-to-order entrees, which are included in the price. It isn't cheap, but we sure felt fancy and special there!
You could go walk around or something, then they'll let you back up with your receipt, to view the fireworks I think. I know if you go to brunch they do that (and we lucked out and got brunch on 9/23 due to the kindness of a fellow Disboard member letting me know she was cancelling).
Reservation is for mid-September. I was hoping I could help you out...sorry, although I’ve read that meals at CG can easily run 2 1/2 hours, so you might be ok. Just relax with that after dinner cup of coffee and drink slowwwly.
Yes you will be too early for fireworks- you will be able to sit there for maybe 2 1/2 hours but getting to 9 will be a stretch. You can probably just walk out to the observation deck after dinner and wait until the fireworks start. Not sure if you can grab an after dinner drink at the bar or even bring one outside with you, but that might be an idea. Good luck and have fun- Cali grill is awesome!!