Hi, we are hoping to travel LHR to Boston next May half term. (2016) 2 adults and 2 kids aged 9 and 5 ( at time of travel)
We have
BA - 238,000 Avios on a Family Account
and
Virgin 170,000 miles on my account

I've tried to slice and dice it but not sure if I'm playing the game correctly!
The cheapest by far is to travel separately - 1 adult and 1 child on BA business and Virgin Upper Class respectively...
But I'd prefer for us all to travel together.
Best I've found is 28th May LHR _BOS out and 6th/7th June BOS_LHR
BA 2ad2ch Business 220,000 miles + £6030
or
Virgin 2ad2ch 160,000 miles + £5850 ( combination of miles/ bought miles etc)

Any tips on how to maximise??
Thanks in advance