Zerg modding question

So, I’m building a campaign dealing with what I can piece together of Egon Stetmans “Mecha Zerg”, the “Simulant Zerg”, the Cerberus Zerg, and how it’s all interacting.
Basically Brood wars 2, but with hopefully a humorously unique spin on it. Over Queen Zagaras headache will only get worse.

Anyway, I’m hoping someone can point me in the right direction of either an already made model (preferred) of units like the Leviathan in the Mecha/Simulant skin and the Cerberus skin.

While I’m done with plot and map building, and have a pretty decent grasp over Galaxy editor, I simply fail at skin making. Does anyone know where to find what I’m looking for?