I personally don't order from online. The basis of meats that I use is mostly chicken and I make my rounds to a variety of stores and sources locally.
Even if you have to use human grade meats from the stores, it is still a billion times better than feeding commercial foods. In the ideal scenario, one would like to feed only grass fed beef or totally organic everything, but many of us don't have good options for that, so we go with what we have available.
I would suggest to start with chicken and work your way up to turkey, beef, pork, fish and organ meats and whatever else you can find.
When you switch them over, you want to start with one thing (initially a mono diet) to allow them to get used to it and then start adding in other things after they are accepting the one thing. They will most likely go through a time of loose stools and then possibly again as you add new foods.
Dogs need to build up different digestive juices when they are switched and this can take some time. But each one will react differently.
What I was told to do was go to the store, buy a chicken, hack it up and start feeding it to the dogs. That is exactly what I did and never gave them another piece of kibble after that. Not to say that is the right way, but it worked for me.