Hi, my name is Mel and I have a 14 month old son who is allergic to wheat. I know how hard it is to feed them fun food, as opposed to adult food. So, I'm not totally sure all the foods your son would be able to eat, but I'll give some things to try. Make sure you read all ingredients though, as I'm not 100% sure. Have you tried the Graduates by Gerber? My son loves them! There are some that look like Cheetos, and there are 3 different flavors. I know that the cheddar one has milk in it, but try the other flavors. Also, the same brand makes things called "pinwheels" made from apples. They are more filling. As for non-dinner foods, I give my son a huge variety of fruits and vegetables. I suggest lots of melon: honeydew, cantelope, watermelon, whatever you can find. Mango, peach, pear and apricot are good because not a lot of people are allergic to them (I don't know if you're worried he has other allergies as well). Strawberries are a favorite, though there is a higher amount of allergies with strawberries. Blueberries, raspberries (now is the perfect time for them! Pick and freeze and feed them to him over the next few months frozen, which may also feel good on his teething gums).
I actually have a harder time finding easy to make dinner food for my son now. He eats mostly fruits, veggies, and cereal. I don't know how many cereals have milk in the cereal itself, but look at ingredients and give your son a handful of kix, rice crispies, corn chex, etc.
If you really want your son to eat the same kind of foods that your older child ate, I suggest looking for a dairy-free cook book. If I found one fore wheat, I know you will be able to find one for dairy! But, I will give you the name and author of my wheat-free cook book because although she focuses primarily on wheat-free, in all recipes she provides ways to make the recipe dairy, nut, egg free, etc. It is called "The Kid-Friendly Food Allergy Cookbook" by Leslie Hammond and Lynne Marie Rominger.
Another suggestion, go down to the nearest Natural Pantry one is on Dimond, one on Old Seward/36th at the University Center) and look around, and ask someone to help you find dairy free foods. That's what I did. There are a lot of options there. Then, once you find the foods you know about for sure, you can go to regular stores and have more luck finding the specialty things since you know what you're looking for.
As for still drinking milk. I suggest Goat's Milk. I know a few kids who are allergic to milk, and we thought my son was also. I was told that Goat's milk is the best thing for kids to drink, because it has so many good things in it (like your milk, whereas cow's milk...who knows what it's been put through.) And, if he'll drink goat's milk, which he probably will if you make him start now, you can give him goat cheese, ice cream, etc. Ask at Natural Pantry, if they don't sell it, they may know of someone who does. Maybe try New Saguya's also (though I'm not sure if they'd have as much as Natural Pantry).
Okay, well I've written a lot, so hope this is helpful and good luck with finding kid foods!
~ Mel