Not knowing the various manufacturer's that may avaiable in the U.K., here in the U.S. I would recommend a lawn tractor with a hydrostatic transaxle or transmission as opposed to a gear drive. Additionally, the belt system driving the mower blades should be readily accessible. some makes of tractor type mowers take two men and a boy to change a broken belt.
As to powertrains, one brand is Snapper and it uses a unique plate system of transmitting the power from the engine to the wheels.
The most popular make here in the U.S. seems to be John Deere, but Cub Cadet is a close second. I, personally, use a Simplicity and have for years. The Husquvarna you mention has only become avialable in the last decade...