If you're short of space, consider a corner of the kitchen (if you don't have corner units)
You will still need to get at the softener, especially for adding salt, sometimes for maintenance.
You can hinge a piece of worktop with counter-flap or bar-hinges
Softeners are very heavy when full, so better standing on the floor than inside a cupboard
Fit full-bore valves, and large-bore hoses for improved water flow, especially if you have a combi. The large-bore ones are more expensive.
Also consider looking up your local water-softener merchant (there will be one) especially if they provide service and repairs. They may sell an own brand and be reluctant to repair other cheap makes. They probably also deliver salt (never carry it in your own car, a single spilled grain can eat a hole through the floor)
