What posuk does one choose at the end of shmonei esrei if one has two names? do you use two pesukim? or take the posuk that starts with the first initial of the first name and ends with the last initial of the second name?
As Menachem mentioned in the comments, there is a letter from the Lubavitcher Rebbe (here) where he says that the previous Lubavitcher Rebbe was instructed by his father to say two pesukim, one for each of his names.
I don't have sources, but as far as actual practice goes, all the people I know with two names (of which I am not one), say both pesukim. I know some Chassidim say the Pasuk of their Rebbe. Those who follow this custom say both Pesukim if their Rebbe has two names