Guild Wars 2

I know there are many threads on this but everyone seems to have differing opinions plus a lot seems outdated. But I just reached level 80 and I wanted to get my gear started as Im still running all lvl 60 stuff. But since this will take a majority of my money/karma i want to get it right the first time. So any help would be a appreciated.

I mainly (as of yet) only play dungeons/world events/random PvE with a staff build. I tried picking up D/D a few times but Im just too used to staff. I also want to have a good amount of DPS while still having some survivability. For that reason I was thinking I should choose Sentinel gear P/V/T so that I can have both power and surivability. Is that a good idea or would zerkers be better in the long run as Eles are mainly wanted for more dmg output.

Also Ive heard you can get gear from karma merchants in Orr but that the stats arent always the same? Im not sure what that means. Like Sentinels wont always be P/V/T?

Like I said any help would be great.