Well I've tried the
Syser Kernel Debugger trial and it refuses to boot. I've been to their support forum (which is a joke) and saw only one thread concerning Vista 64 and the admin stated there was no support for 64bit, that post was from '07 though.
Judging by the way they treat the customer queries on the forum, I think I'll leave that app well alone.
Ollydbg is the best choice, as stated earlier it just doesn't happen to work with this particular game. I'll continue to use Windbg for now.