By no means am I a digital artist. The software I have for tweaking photos is nowhere near professional level. Heck, it's barely substandard. But, I got the crazy idea before you in my head and I wanted to see how close I could come to making it happen.
As far as I have been able to learn, the Devastator art was originally made by Javier Carabajal. The Pacific Rim art, I'm not sure. The closest I have come to finding an artist is the name "Abe" on one site, but that could simply be who submitted it.
http://cneterer.deviantart.com/