Originally Posted by
cazic99
Will SFO-LHR-AMS Trains to Paris PARIS-LHR-SFO work?
Yes, it will work just as well. I've done something similar countless times.
Personally I would look at whichever flight options are available via BA first, then choose the best of among them to suit your preferences. Whether you fly into AMS or CDG (Paris), and return from the other makes no difference to BA, as long as the flights are available.
Either way, you're booking an allowable 'open jaw.'