Do a Google search for DIY backpacking meals. You can find a lot of alternatives to the more expensive Mountian House like options. Most ingredients are available right at you local grocery store. We travel with all dehydrated ingredients for the most part. All we need to do is boil water to cook a meal.
As for packing meals. When I backpack, we pack individual meals in either zip lock bags or we vacuum seal meals. For example a breakfast consists of an indiviual packet of instant Oatmeal, some dehydrated banana, an individual packet of Trader Joe's instant coffee, 2 Nutri-Gain bars, a small napkin and a wet wipe. That's an entier breakfast. That all goes into one small ziplock You also want to get as much air out of the bag as possible. Lunch consists of a meal that does not require cooking. You're usually on the trail so you want something fast and high in calories and fat. Summer sausage, those indiviual round cheeses, a couple small tortillas, an individual package of Keebler peanut butter crackers , and a snickers bar. Again this all goes into one quart size Ziplock freezer bag. I put all my individual meals into one food bag.
Search freezer bag cooking. Really good way to rehydrate meals. No mess, no cleaning.
There's a lot of great stuff available right at your local grocery to put together some really good meals. Some indiviual ingredients include: Knorr Sides, foil packets of tuna or chicken, Trader Joe's indiviual packets of instant coffee (include sugar and powered milk), microwave Mac and cheese, Indiviual ice tea packets. There's a lot of really good DIY meals on backpacking forums. Just make sure you test any meals you try at home before you hit the trail! This way you know what agrees with your system.
Good luck!