I personally dislike dbol, I am partial to drol' but it definitley shouldnt be in a first cycle. If anything, you can FL your Eth or cyp, or you could use T. Prop the first two weeks, and the last two weeks before PCT as your waiting for the longer ester of Eth or Cyp to clear. But, that may be getting a little too fancy.
As for the dosage, although 600mgs may seem high for a first timer, at his weight and experience, I dont see too much wrong. And recent studies have shown 600mgs to have the greatest affect on satellite cell activity, IGF-1, and GH release.