Gainsy, actually Beneden Healthcare is a better option. This is an NHS assist rather than an NHS replacement.
You start with the NHS then go to Beneden where the NHS cannot handle the problem in time. It is about £10 per month for the whole family.
Once you are a member then you can also take up Best Health at £31 per month (top benefit) and they pay out £75 per day for hospital visits, £400 pa for dentistry and optical, £600 for chiropody and osteopathy etc.
Members of the services and families are eligble. For my back I just went to the chiropractor, no doctor, then submitted the bill. Money straight in the bank.