John as others have suggested avoid Hornby DCC controllers. There was another thread on here only last week highlighting the limitations of a Hornby controller that could not even be used to reset a decoder to default values.
Check out starter DCC systems such as: Roco MultMaus, NCE PowerCab, Bachmann Dynamis, and Bachmann EZ Command
The next level up is Lenz, Zimo, GuageMaster, ESU and NCE ProCab
Recommend you invest some time checking out the ergonomics of the various systems cabs, button and control layouts, etc, throttle sliders v rotary knobs v buttons, etc. Its a good idea to download the manual for each system and have a good read. It will give you a good idea which system will suit you.