Let me welcome you to Flyertalk and the BA forum holidaylady. It's good to see you here and I hope we will see more of you.

I would hope it's just the seating that will be an issue here, since you can guest your boys into the lounge and Fast Track, and between you, you will have a pretty hefty baggage allowance all told. And there is no way around that since to share a booking you need to travel together in the same cabin, that's just a hard and fixed rule of air travel (and not just for BA either). In that situation I would mentally add the seat cost to the ticket, and they will have seat selection at OLCI anyway. The trick to that is not to print your boarding pass immediately, but to wait until the "right" seats come up, which may happen a little while after Online Checkin has opened.