Hi Bradley!!
Wishes is such a magical way to end a day at the Magic Kingdom!! It still takes my breath away each time I see it!!!
The two restaurants that somewhat face Cinderella Castle and that would provide you with the best possible view of Wishes would be the Plaza Restaurant at the end of Main Street, USA and the Crystal Palace. These will not offer 100% unobstructed views, but there is a good chance of catching Wishes.
Your best bet to see Wishes and have a bite to eat while you do so is to book the
Tomorrow Terrace Fireworks Dessert Party. While it isn't dinner, you can still eat and have as great of a view as possible at the Magic Kingdom. There is an extra fee for this party and I would recommend making an Advance Dining Reservation as soon as possible if you are interested.
Another place we love watching Wishes from is 'Ohana at Disney's Polynesian Resort. When Wishes starts the lights are dimmed and the music is piped into the restaurant which creates an awesome environment to watch Wishes!!
Thanks for your question and have a magical day!!
Scott