I would feed the cheapest cut you can find. You don't need anything expensive. The fat content should be anywhere from 15 to about 25%. It doesn't have to be accurate. You don't want excessive fat nor do you want lean fat. Although, in some stores you can only buy, as an example, lean ground meat. In these situations that's what you have to feed. But 15 to about 25% fat is better.
I am not familiar with all of the different beef cuts and so I don't know which one to really suggest. Myself, I usually buy meat chunks or stew chunks. But sometimes I also buy larger slabs of meat and just cut them into smaller pieces for my cats. For a larger dog, this isn't always necessary as they can obviously eat larger pieces. Although our pets can eat large pieces of meat, were designed to do so and although they can rip the pieces of meat smaller, I still prefer to give meat in sizes that are appropriate for them.
While I like to give pieces of meat in sizes appropriate for them, it also depends on the meat. Ultimately, our pets can easily take even the largest piece of meat and turn it into a size they can eat. When I feed my cats whole fish or when I feed some dogs whole fish, they literally crush the fish into the right size and then swallow. But fish is a little bit of a softer meat. With beef, it's a little bit tougher. Even though tougher, my cats will cut their beef into sizes good for them — and a dog can do that too. But dogs are better at ripping meat than slicing meat. Cats chew with their molars to slice a meat off while dogs rip the meat off.
So a cat will walk to their prey and have their head parallel to their prey — essentially sideways to their prey so they can chew with the side of their mouth where their molars are. They use their molars to slice off a piece of a meat.
Conversely, a dog goes head first into their prey, sinks their teeth into and then starts walking backwards and pulling with their neck as they begin to rip a slab of meat off. Once they have a piece, they will chew through if it is too big but the tendency is to swallow it whole.
So dogs are not as good at slicing meat as cats are — although dogs do this. But in the dog's excitement to eat, they don't always think about making the meat smaller!
So for safety, I just prefer to give size appropriate meat. We don't need to make the meat super small. They can swallow huge chunks but when it is obviously too big, that's when I cut the meat smaller. However, you can throw a slab of meat onto the ground and your dog will still find a way to chew it to get the correct size of meat to swallow. If the meat was big enough, then the dog would sink its teeth into the meat, put its paws on the meat and rip a piece off. But seldom can we feed meat in such a large size without ultimately wasting the meat because as much as a dog can eat, the slab of meat would probably still be more than what they can eat.