well according to shakespeare's writings, the illiad, and the NB reps at the dubai conference it is patroclus; the traditional spelling.
in the past hundred years or so greeks have replaced most C's with K's when translating to english for phonetic ease, though, and all the game blog'ish sites today say patroklos.
given the tendency of calibur to be within a time period and not really care about whether or not we can pronounce a name (hilde, Scheherazade) i am pretty positive that it is meant to be Patroclus. i guess we'll have to wait and see what daishi says directly.