1. Play a dragonborn, and convince your DM to let you use psychic as your breath weapon type.
2. It'd be nigh-trivial to come up with a quick and dirty half-dragon elite template. Slap some resistance, a breath weapon, and perhaps a clumsy fly speed on it and you're done. That said, there's probably a reason they haven't done it. As far as I know (not having read the
4e Draconomicon)
4e dragons lack the ridiculous fecundity of their
3e brethren, and the various "dragonspawn" creatures seem much more compelling than just applying a generic template to things.