Yes.
Unless you enjoy pulling engines out & rebuilding them get a used commercial mower with a horizontal engine.
The sumps are about the size of a big dinner plate with oil about 1.5" to 2" deep so any sort of a slope has the pump in air.
The ZTR's with a steering wheel will mechanically handle slopes a lot better than the lap bar ones because the front wheels are not free to swing in the breeze.