Have a word with Rob at Southern Cross Yachts in Plymouth. Here's a link to their "contact us" webpage. Rob and his team have all the contacts you would need if they cannot help themselves. Remember to tell him that Peter from the Yard recommended them.
Tell him Peter from the Yard passed his details to you. I think he's in the process of setting up a charter Rib/bareboat so I'm sure he will be looking for customers very soon.
He used to own the South West Rib Centre, based in Plymouth they can provide you with a Rib if all else fails. You need to speak with Pete (not me) in there now and again tell him Peter from the yard recommended you. They have some nice ribs in on brokerage at the moment but also stock new zodiac, ribeye, bombard and Avon.
Here's their details
Hope that helps, let me know how you get on with both leads.
Peter @ Boatsandoutboards4sale ~ email@example.com
~ 07930 421007