Hi Folks,
New to flying and must start out with the standard question - which airline FF program would be best in my situation? I expect to fly US (SFO) to Asia (PEK, TPE) about twice a year (J class). SFO to BOM/DXB once a year and SFO to LHR once a year (Y class). About once a month within US (SFO/SJC to random places within US) for which I currently already have a SW RR account.
Would appreciate your recommendations for choosing a FF program in this situation. I am considering BA, EK, CX and SQ, but am open to others.
I like EK and BA because I can redeem a free RT to LHR/DXB at some point, but CX is very well connected within Asia.

But additionally, I'd like generic inputs on what programs amongst these are considered most rewarding in terms of redeeming roundtrip/upgrade rewards and quicker in moving up the tier status?

Thanks.