I would reccomend that you do not take the Virgin, easyjet option. Not because of Virgin but the fact that you will have to change airports. The Easyjet flight leave from STN about 1 hours bus ride from LHR. Beacause of this you will have to collect your bags and recheck them in for the connection.
Also this itniery would have to be purchased on two tickets and as easyjet is a low cost airline things can and do get out of shape and you will be on your own.
For this reason I would book it all through BA or AA/IB.
Regards