I know VS have leased a few aircraft in the past, definately the first two 747 classics were leased. They have also leased from martinair in later on. But they own aircraft now and have 'buying rights' on 787 so that must mean they will be buying them straight from Boeing albeit making use of amortization.
Well, we know the financial details will always be company confidential. Neither the airline nor the manufacturer wants the details of any deal being made public as it compromises their position for future bargaining. One thing we do know is that Virgin isn't in a position to write a cheque for the full value of the aircraft up front, so their has to be some kind of financing going on to enable the purchase. Much like US Airways has a huge loan from Airbus which finances their purchase of a large number of their aircraft.
Whatever the deal is, the thought of cancelling an order for an aircraft makes that money available to fund pay rises is without substance since the money doesn't exist unless the aircraft is flying and generating the revenue.