Seriously, for the cost of a 20" x 30" -- $235 , you could pick up a used EOS 10D kit (or better even) and start shooting your own. Spring for the 48" x 72" -- $995, you can get the body as well as a couple lenses/filters. And that's just a print, not even licensing!
I thought the headers thumbnail had an interesting composition, but then I noticed you can clearly see him crouching in the right-most pipe. Quite distracting. Rest a kinda meh, alright, but I think the wide-angle stuff is just plain overused here.
I'm not really impressed. I like Shaman's better. If he had turned the bike so the sun would shine directly in the direction he was taking the pic from so that it would have lit the front of the tank and radiator it would have been even better.