Just to clarify, any professional cleaner that is an actual cleaner at all, services their vacuum daily or at the LEAST every few days. If they don't, they deserve to buy a new vacuum regularly. So there is no house in the world that should be too much for a professional cleaner using their own vacuum cleaner. Even a regular person that has dogs/cats needs to service their vacuum every time or every other time you vacuum. There is no vacuum that magically cleans itself. 99.999% of the vacuums people throw away are easily fixed with 3 minutes of work. I see vacuums all the time by trash cans and pick them up... bring them home.... unclog them & clean the beater bar and either use them or give to someone that needs one. I have about 10 in the garage right now that I fixed with 3 minutes of work.
With that said, all you need is a vacuum that is made for floors since you want to vacuum them. That means buy one that has the button so you can stop the beater bar when using it on a floor. No matter what brand you buy.... it won't clean itself.