I'm a big fan of the Knight. But IMO, the Dragon Shaman just isn't worth it, regardless of whether you multiclass or go gestalt. Let's examine what the DS gets:

BAB: 3/4 - not enough to use Power Attack feats.

Skills: 2 Skill Points per level from a poor list. You can't get Spot and Listen, so you can't be the party scout. You can't get Diplomacy or Sense Motive, so despite your high Cha you can't be the party face. You have Search, but not Trapfinding or Disable Device. You can't get UMD or Tumble. And some of the Totem choices add very odd Skills combinations (Blue adds Hide but not Move Silently, Bronze adds Disguise but not Bluff, etc).

Draconic Aura: One of your two core class abilities. It's a great idea. But unfortunately, it scales very slowly, and most of the auras are poorly written. For example, Senses gives you a minor bonus to Listen and Spot, which are not class Skills. Vigor only works up to 50% of your hit points.

Breath Weapon: Your other core class ability. It's nifty. But unfortunately, it also scales very slowly. At 20th level it deals 10d6 (Reflex for half) damage. That's an average of 35 points of damage per enemy, IF they fail their Save AND don't have Improved Evasion AND they don't have energy immunity or resistance.

All of the other class abilities can by affordable magic items.

So in summary, I think it's great fluff, but a poor crunch decision.