Grumpy_Mike:
Well most restrictions imposed by a license are a bit academic because if some on wants to break them you have to, one find out and two be prepared to splash out the cash to get lawyers to take to to court. The only ones who will make money are the lawyers.
Couple things... License at least lets you express your intent, so it's clear to the receiver what you expect from them. Often times that's good enough--many people are willing to respect the wishes of the author.
Second... In this case, the law can actually help you. Let's say someone else uses his CC-NC design, and sells it through ANOTHER botique art and design shop. It can be effective to send a cease and desist letter to the shop selling it. If a supplier looks like it might expose you to legal hassle, often it's not worth bothering with them. C&D letters are nowhere near foolproof, they definitely have a non-zero success rate.
Personally, I think a CC BY-NC-SA license is totally appropriate for this use.