Hi Bria!
Thank you for visiting the Moms Panel!
I love all the Magic Kingdom resorts, and those situated on the monorail link are very convenient for travelling to/from the park with young children.
Disney's Contemporary Resort is the closest resort to the Magic Kingdom and even has a pathway for you to walk to the park (10-15 minutes). It is also great to see the monorail go right through the centre of the resort. The gardens rooms are situated overlooking Bay Lake or the pool. Some of the rooms facing Bay Lake may give you a longer walk back to the main Tower, but you would have a very peaceful location. Not many of these garden rooms have balconies, but the first floor do have patios. Also, this is the home to Chef Mickey's which would be the perfect place in which to celebrate your boys' birthdays!
Disney's Polynesian Resort is a very beautiful place to stay, and if you request a theme park view you could watch the fireworks from your balcony! If not, you can still see the Magic Kingdom fireworks from the beach. You have a good choice of restaurants to choose from, including the character breakfast with Lilo and Stitch for 'Ohana's Best Friends Breakfast!
Both of these resorts would be great choices! If you have any other questions, please come back and ask me - I would be happy to help you plan your magical vacation!