Croc,
Virgin does not hire direct entry captains for either fleet, there are plenty of SFO's with with sufficiant experience within the company, many of whom have been waiting for years for a command and lots of prospective F/O's in the hold pool to replace them. Sorry!
By the way I see from your byline that you are US based, you would need an JAA ATPL to work in the UK. If you have one then providing you have the right to live and work in the UK you could apply to Virgin as an F/O. A 737 rating would be perfectly acceptable, there are loads of ex 737 drivers in the company, myself included.
Good luck