Hard to say.
Personally, I'd like to think Kirak would be superior. He easily overpowered Vader's initial Force choke, and he seemed to be Vader's superior during their final clash.
*But I'll also note that this was a n00b Vader(literally a few days off the operating table), and his armor was heavily compromised at the end.
Originally posted by DarthadiIt's from Marvel's official solicit for issue #3. Could very well be canon.
Kirak's accolade is from a publisher IIRC. I don't think it's necessarily canon.
Vos should win.