I have done pretty much all those options from PRG to ATL.
In your case I would tip the scale to the AA/BA option.
Americans PE class is a domestic first-class seat. I do recommend the bulkhead. While I tend to give more kudos to AA PE class over BA, I wouldn’t sell BA short. It’s still a good seat and a far cry better than economy. Again, I would still recommend bulkhead.
East bound having the long haul going directly into Munich is a nice option. Returning the morning flight out of PRG has always been hassle free for me and you arrive and depart from terminal 3 at LHR (when I traveled, however I know this can change)