Well, I can think of three different ways you could do it.
The simplest would be like others have suggested; just do a series of minor/cosmetic changes, replacing the Oriental-centric abilities with more dragon-related ones.
> Instead of gaining DR-penetrating Ki Strike abilities at 4, 10, and 16, the unarmed damage would switch to the dragon's damage type at level 4, and gain the ability to ignore half of elemental resistance at 10, and all elemental resistance (or half vs. immunity) at 16.
> Instead of Quivering Palm and Abundant Step, give the Dragon Disciple's Breath Weapon (2d8 and 4d8).
> Instead of the Monk's WIS AC bonus being effectively a "dodge" bonus (lost when immobilized but works against touch attacks), make it a Natural Armor bonus (which works when immobilized but not against touch attacks)
> Instead of Tongue of Sun&Moon, give Blindsight 30'
> Instead of Empty Body, give one of the dragon's best spell-like abiliites 1/day.
The next simplest would be to overhaul the Dragon Disciple PrC such that it was aimed more towards Monks. Remove the spell requirement, Natural Armor boost, bonus spells, and claws/bite, but allow it to continue the Monk AC, speed, and/or attack progressions. So, at level 6 or 7ish, Monks in your campaign would switch to this PrC and tap into the Dragon spirits. They'd get stat boosts and such, making them stronger physically, but at the cost of the random spell-like abilties and fluff abilities high-level Monks get.
The most complex option would be to redesign the Monk class altogether. IMC, we did this, by building the Monk in a way that allowed the player to mix six separate Paths together, because our main complaint about the core class was that it was too "railroady", giving the player no real choices as to what abilities he received. Most other melee classes either give you a choice of spells (Ranger, Paladin, Bard), feats (Fighter), or skills and high-level abilities (Rogue); only the Monk and Barbarian get forced into one specific path. Coincidentally, we also totally reworked the Barbarian.
The result of our Monk tweaking was posted
here. Of course, that post was from almost four years ago, and we've updated it to 3.5E since.
You might want to try something similar, and make a handful of different Monk subclasses based on each dragon type.
