I’m looking for the best way to play as a Dragon with all of its special/supernatural abilities. I don’t care whether this is through a spell, animal companion, cohort, being a dragon or any other method. Balanced House rules will be ok.
I know I can play as a dragon by taking it as my race, taking Dragon HD and applying a LA, but this does not really give me what I want – an ECL 20 Gold Dragon is spellcaster level 1, size large, no spell resistance, no frightful presence and a pitiful for ECL 20 6d10 breath weapon. It's powerful because you have better stats than a normal dragon and magic items, but it won't play any differently than a fighter with magic wings
The target would be something that lets me play as an old gold dragon with no equipment at level 20 instead of a young gold dragon with +5 mithril full plate, +6 dex/str/con, +5 saves and all the other cool stuff from items.