may want to try and deposit $100k in fidelity using AA's offer to get you another 50k miles on AA.

I am traveling on CX and had to redeem one ticket on BA and one on AA for the same flight. I would recommend reserving the first ticket with AA first, then calling BA to book the second. BA won't let you hold tickets, so sometimes it is a bit challenging to coordinate. Also, BA and AA don't always have the same availability.