I have been mowing our acre lot (yes, really!) with a 100 dollar 20" Yard Machines non self propelled mower for the last two years that I bought about 10 years ago. We have a 42" rider and it is good but is parked in the shed because I need the exercise and don't like the rough ride. There is little to go wrong with the Yard Machine unless possibly if the wheels get loose or crooked but so far, not yet.
Tecumseh made good engines but as you may know are out of business. B & S are good also.
Our last non self propelled mower had large rear wheels but it did not matter for me. I am curious to know why you want the large rear wheels.