NWSRG
I have not flown in either a BA 787 or 380 but have done plenty of hours in other peoples 380 (LH/SQ/EK) and a little time in 787 (ANA). For me it would be 380 every time, as others have said the much vaunted 787 windows are not all that they are cracked up to be. Also as has been said both Virgin and BA have or are having issues with engines so you may not be on 787 anyway. As for service I will not bore you with BA experience, suffice to say they are on my no fly list. However I had been using Virgin a little from Man to Atlanta to get to Houston prior to Singapore starting their direct route, and can not say they really were that impressive either.
As for entry point, like others have said stay away from LA and maybe use alternatives. Unfortunately Houston is too far away for your destination as I have found them to be very quick in clearing immigration in my experience. If not using air miles or committed to a set carrier maybe Shamrock could be the way to go, and save some money as well and get pre clearance.