I think ultradns.net is only the DNS-server.
The owner of the site should be OLX in New York
Did you try to contact them?
http://ciudaddemexico.olx.com.mx/contacts.php
http://www.olx.com/contacts.php
I don't know how this works with mexico and copyright ingringements, but since they seem to be located in the US...
But concerning your ranking. I think you're at this place because of the image names and your page rank at google search. If i search for "koi pond deck" in the normal google search your page is on top.
http://whois.gwebtools.de/woodsshop.com
So i would say you can manipulate the images and keep the names and it should work, but no guaranty!
Maybe you should ask a professional webdesigner and a lawyer for more information...