I mow with a 72 inch mower and trim with a 48 inch. Wouldn't have anything smaller if your goal is to save time.
I use farm tractors to mow because I don't like the ruff ride of a ZTR not to mention the dirt and dust they stir up.
A mower spindle isn't that expensive. It's like saying I want a new car because I need to buy a new battery.
Ever consider getting an outrigger mower, one you can pull behind your rider. Years ago, I made an outrigger and my kids wouldn't mow with out it.