similarly: M111

I have a few choices here.... I can't be running 0W stuff because my area is always around 0C... I have

10W30 - dino oil or Castrol Syntec
10W40 - Royal Purple
5W50 - Castrol Syntec

what do you guys recommend?? The engine sees vigorous excercising everyday ( at least hits red line once a day). So far so good but oil change is coming up in 2000km.