Well, I don't know how much fine details you've allready filled in and how much you'd like us to produce ourselves, but here's a go at it (thinking out loud):
- Vestennahjavvar (guardians of the people) They could be "enforcers" of the dragon priests, some kind of bodyguards, with two clans, one for the "good" dragons and one for the "evil" dragons, families closely linked with dragons, with dragonblood running deep in the family. These two clans would have a blood feud going back thousands of years. My character could either be on a mission, disgraced because his priest was killed, or on the run because he was framed for the murder of his brother who was a priest... If it's a bit more structured you could have a dragon-disciple-like prestige class of some sorts, or use the tattoed monk or the inkyo monk from oriental adventures as prestige classes.
-Aesturruvand (wild men from the north) They could be wild men from the waste, looked upon with awe by their fellows. Maybe from a clan in the deep ice mountains. They would be feared reavers, going berserk (maybe allow some mixing with barbarian classes, or allow barbarian rage as a feat, or say flurry of blows means the barbarian unleashes his rage?), and being seen as a bit of a rabid dog, having him on your side is slightly better as having him on the opposite side?
-I was thinking about allowed "monk" weapons. Dragon claws (=sai) look like an option, and maybe hand axes, but that's about as far as i get.
I myself kinda prefer the first option, but I don't know if that fits in your world.