Same bin I had in mine.
S = flux (brightness) higher is better, but more $
X1 = tint. X1 is close to my favorite, it's slightly warmer than what appears to be the most popular, W0, which, to me, is a little blue.
K = Vf (forward voltage) Lower will give you a higher current draw and therefore brighter light, caveat is if you driving direct, too low means you may toast your star