Hi Joe,
Walt Disney World does an amazing job meeting guest's dietary needs. I was a vegetarian for many years, including a time where I did not have any animal products such as eggs and milk. I made sure to include a notation in all of our dining reservations about my restrictions, and I confirmed those with the waiter/waitress, too, when we were seated at the restaurant. In fact, in many cases the chef came to talk with me and even made food items off the menu.
More information about
Special Dietary Requests can be found on the included link. Within this link are a list of counter service restaurants that can accommodate common food allergies or already have items on the menu.
As for the best dining plan, that can really vary with each guest. However, most guests book the
standard Disney Dining Plan. Through this plan, you'll have a table service meal, a counter service meal, and snack per person in your party for each night of your stay. You'll also have a refillable mug for each guest in your party. We have done this dining plan more than once and had plenty of food.
Please let us know if you need more information or have more questions.