Doesn't the Dragonborn of Bahamut thing give +2 Con? It causes you to lose most non-stat racial features, which might be a dealbreaker, but it's a +0 template that adds +2 Con -2 Dex among other things. You couldn't have the bonus feat for being a Human, for example. You would keep the Human "any" favored class, though, which is nice if you want to do any multiclassing. The -2 Dex might be a problem, given the Dragonfire Adept's dependence on light armor though.
That said, as long as you're cool with playing a Good character that actually LOOKS like a dragon, the Dragonborn of Bahamut template seems perfect for your purposes. Plus, you don't have to take the Aspect of the Heart to get a dragon breath, though if you do it gives you another separate form which--I think--could benefit from metabreath feats and breath tweaks. Wings might be more useful in the long run, since that's the one benefit Dragonfire Adept doesn't innately confer on its own.
If your DM allows it you could even take Lesser Aasimar for ultimate stat bonuses (+2 to Cha, Wis, AND Con, -2 Dex), though you keep essentially nothing else. If you can find some way to get a different stat to AC other than Dex (esp. Con or Wis), though, it'd be sweet indeed.
