Here's what we are looking for, high level - everything is workable and negotiable.
We're looking to essentially redesign all 5 of our Casino Games to be (a) more consistent, and (b) responsive. You'll notice all our games right now pretty much only share the top nav and footer, than stray pretty far on the games themselves. Bitzino has done a very excellent job at offering many games - but keeping them consistent from a look and feel perspective.
In terms of delivery - we'd first be looking for mockups of all the games which show 'consistency', these can be in png, gif, whatever. I imagine we'll have a round or two to iterate on them as feedback will be provided.
Once we agree upon the mockups we'd be looking for either illustrator files, or html / .js / .css which we'll then plug in to the backend.
We'll pay more for the html assets then the illustrator files since we have to cut them up ourselves.
Also - top nav and bottom footer need to stay, the rest of the real estate is your to paint with
It seems ur site is already responsive. So u might have some very specific requirement. Its good if u xplain that, so that the devs may understand what u really want and quote accordingly.
Shoot me a PM and I'll send on sample work. Would be myself and graphic designer friend, ready to go asap.