The synergy between Dragonlord and animal forms isn't actually too great, I would recommend barb over it hands down. A lot of the melee power you get in animal form (21 points) is locked behind using barb or animal rage, which you get so many bonuses for in the Nature's protector tree. If you had to make it work with DL, 12 druid seems like all you would need as it gets you Great Maul, 15 only really gives you 8th level spells so you can have heal. 8 DL would give you extra feats, so you could take dodge+mobility, WW and Spring attack. Alternatively, 8 barb would give you Improved Uncanny Dodge, better rages, and more DPS. Only downside is you'd have to go through a universal tree for your trance.
For feats I would start with power attack and then do the 3 natural fightings, fitting imp. critical [desired choice] in when you can. Make sure your first three level are druid to unlock the natural fighting line, and then do whatever other class you're splashing.