Is there a Class that offers more Dragon Transformation than Dragon Disciple?

[Zanos]

Option 5: Wish

I know Wish is a meme but hey if the DM allows the "LoL Wish can do everything" version then it can work. Same for miracle.

Savage Species specifically lists as wishing to permanently turn yourself into another creature with all their abilities as an 'unsafe' wish, but then outlines rules for how to make it unsafe if the DM wants to discourage using wish for this. TL;DR having a +39 spellcraft bonus makes it irrelevant.