I'd vote for "both" - since I'd love you to be hosting the archive on the original domain for the moment, but I have more faith in them not Failing to Deal with Stuff than you (and were I in your shoes I'd be thinking the exact same thing about myself) - and, also, I'm kinda hoping the internet archive will outlast us both unless we get immortality soon enough.

Also, [insert gushing praise here], I loved k5 back in the day.