Dinosaur Models for Pain Engines

Hello, Dark Dudes. I am a conversion enthusiast and an insane person, so I decided to add some more Talos to my army (2-3 I think, to have a full Corpsethief) and thought to myself "I already have 3 Stormfiends as Talos/Cronos, lets crank this up a notch!". So I decided that the next logical step is converting a Triceratops or Tyranosaurus/Carnotaurus model into a Pain Engine.
Any suggestions on what models can I get to make this dream reality? I know Tamiya has some of those, but they are not "chompy" enough in my book.

Ive got a white metal Triceratops in the right scale, but its not chompy...Lets face it, triceratops is more of a horny guy...

Your best bet would probably be Taimya...Though both GW and FW do lizardmen stuff

Oh yeah, I forgot they existed. A carnosaur would be nice as a pain engine, a stegadon would make a nice cronos/mobile disco platform. Will look into them if I won't find anything more interesting.