"Keep On Em"
If you go with a design shop, make sure you keep on them. I tried two, and got NO responses from them at all.
SO, in the end I designed everything myself, then connected with John Stahr to finalize the details and have him paint the job.
Out of "professionalism" I informed the companies I originally contacted that "Since I have not received any response from you regarding the design of my project, I have elected to work with a local vendor...."
Surprisingly I got an immediate response to that - apologizing for their lack of communication. BUT, ALAS, that's a bit late in the game.
If you really need some external design assistance, make sure you bug the **** out of them to get them to respond. Otherwise, you may not get your project completed in what you expect to be timely.