I think you have chosen some wonderful restaurants! You will be pleased with going to any of these. Here is our take on the ones you have chosen:
Ohana (dinner) - This is one of our favorite places to eat. The presentation of the food is nice. I love that they bring huge family sized servings to the table and we love the 3 foot long meat skewers. Every bit of the food is delicious especially the wings and the most amazing bread pudding I have ever eaten (I hated bread pudding until I had theirs, now I crave it all year).
Crystal Palace (breakfast) - The restaurant is beautiful with a nice view of the castle. It takes a while for the characters to get around and we consider the food average. We have not eaten breakfast here yet so our experience was based on dinner.
1900 Park Fare (dinner)- We loved their buffet. The characters were amazing and the 2 step sisters really cracked us up. We were lucky to have been seated in the front area of the restaurant right outside the door the characters came out of, so we were the 2nd table they visited. They spent quite a bit of time with the kids. The buffet, was in our opinion, one of the best we have eaten at Disney with something for everyone. Not to mention, you can purchase a picture of your family in front of a cinderalla mural (we let them use our camera to take a picture of our kids, but their photo turned out so nice we ended up purchasing it).
Wispering Canyon (dinner) - The food here is good if you like BBQ. I would rank it a 7 out of 10. We have the family skillet and we all enjoyed it. The fun here however, has been hit and miss. Sometimes the servers are great, but others we have had didn't seem to play along. If you go here though, be sure to ask for a large drink or some ketchup.
Our kids were able to do a stick horse race through the restaurant. Your DS's might enjoy the western theme.
Chef's de France (dinner) - Beautiful location, wonderful views, and delicious food. This is a great change of pace for our family when we visit. I think the servings are somewhat smaller than other Disney eateries, but I think the atmosphere makes up for that.
Akershus (dinner) - You do get a free photo here with a princess and even though you have DS's our 12 year old loved having his picture taken with Belle (our princess that day). They have a nice cold buffet bar that you can munch off of while you are waiting for your main course. We tried a little bit of everything and enjoyed it all. My DD (11) even was brave and tried the lamb stew (which she loved). There are several princess' who visit with you and they seemed to get around the room pretty quickly.
Garden Grill (dinner)- This is one of our favorite restaurants, however with that being said, we eat alot of fresh veggies and fruits and a low fat menu at home. Some of the food, we were told, is grown right in the greenhouse there at Epcot. We enjoyed riding "Living with the Land" just before our reservation so that the kids could see where some of their food was coming from. On a side note, I highly recommend a tour of the greenhouse. It is very affordable and will give them a closer look at how the food is grown and they may have the opportunity to feed the fish or release ladybugs. The restaurant rotates very slowly in a circle which my children loved. They had never eaten in a restaurant the moved so they thought it was really cool. Most of the veggies came out blanched so if your kids want their veggies soggie they might not like it too much. The catfish however is wonderful and the character interaction was great!
Boma (dinner) - It is almost worth eating here just to see the hotel. The buffet had some interesting items on it and we were brave and tried several of them. The best part of the buffet to us was the selection of hummus' and desserts. Yum!
Mama Melrose (Fantasmic dinner) If you are planning on going to fantasmic, I recommend getting the fantasmic dinner package. You don't have to arrive so early to the show and you get to sit in a special section that has a great view of the action. Our experience unfortunatly at MM was not very good. The food was probably a 4 and our server was even worse. This is definatly not the norm at Disney and from what I have read on other reviews of MM, I think we just had a bad night. The dining room is kinda dark and I thought it was a very romantic place to eat. Of all the places we ate this was the place where we waited the longest (we try to get reservations as close to opening as possible, so that may have played into why the wait was so long).
Hope this helps you out. I think you will be happy at any of these choices. Have a great vacation!
, DH (34) 
, DS (7) 
, DS (6) 
