There are now no Bell 222's left on the 'G' register, so in theory, you shouldn't be able to charter one in the UK...but that leads back to the whole lease/AOC issue which has been covered in depth elsewhere on this forum over many years...!
I think the aircraft Savoia is referring to is N22ZW...see
Heli-Charter Operations (The Airwolf Experience). Don't think it involves flying
in the 222 though, but alongside it in a JetRanger or similar.
As far as I know, the Leeds-based 222 was on the 'N' register, so would not have been available on an AOC. Not sure if it's still based in Leeds or not - no harm making enquiries I guess!
I think Executive Helicopters in Ireland had a 222 on their AOC at one point (EI-registered) if you would consider a trip to Ireland, although not sure if they still do?