It's too bad Crossblooded and Wildblooded won't stack by RAW. But if your GM will allow them to, make your sorcerer bloodline crossblooded Draconic / Arcane (Sage). IF (and only if) you can do that, you can dump CHA. It also depends on what flavor of dragon disciple you wish to be. If you want to be the traditional melee monster, and you can use Crossblooded / Wildblooded, I'd arrange my scores like this : STR 15 DEX 14 CON 12 INT 16 WIS 8 CHA 8
with bonuses going to STR or INT as appropriate (though the DD PrC takes care of both scores nicely)
If you can't crossblood / wildblood into the Sage bloodline, then I'd consider arranging like this :
STR 14 DEX 11 CON 12 INT 10 WIS 8 CHA 16
Obviously the first array will take better advantage of your racial modifiers plus the DD modifiers, so try to talk your GM into that. Alternately you could go Bard, but that's probably going to wind up with much the same array as the second set.
In any case, have fun with it!