I just found out about the "Model A" cognitive function system most commonly used in Socionics, and it seems to be a lot better than Beebe's system.
It divides the functions up into four groups, the ego, superego, superid, and id. The ego is made of conscious functions while id is made of the unconscious. The "super"s are just the weakest two from each side.
And go by your first two functions when picking out your Socionics equivalent. For some weird combination of reasons (socionists' general aversion to the MBTI among others), an equivalent system hasn't been much looked into.