I have all these about 200 roms. The developer that made them gave them to me. He even has source code.
The story is he made them and then everybody in china stole them and started using them for their handhelds and plug and plays, Dreamgear just buys stuff from JungleTac which stole them from this guy.
I believe him because he has some other undumped and unused stuff like 10 or so Genesis games based off popular flash games (gravity duck, zuma, Angry birds (I think this one is dumped actually)) and some other.