I very much doubt we would buy any for this sort of usage we're far too skint. It's almost nailed on that Crowsnest will be a Merlin based platform and as for refueling from the carrier it's not planned or budgeted for. The Americans would have to offer an incredible deal for it to happen which I can't really see occuring.
That and the MOD already ran a study about using a V22 as a platform when Crowsnest was still MASC.