Best depends on fit and plug being used. In my Knights the best has been Win209 and Fed209A. I see very little difference between the Fed and CCI209M. I use the CCIs in my NULA because its what fits the best.
I always recommend the Win209 for starters. Keep the flash channel clean and you should not have any problems. Mag primers just build carbon faster in the flash channel and could even possibly wear the flash hole faster. Only use mags if you NEED them such as in extreme cold or in a marginal quality breach plug.
Since you are making the trip, check and see if they have some Fiocchi 209s too. They are a good primer for CVAs and usually pretty cheap. They are short so you may need to adjust headspace or use an o-ring in the primer pocket.