I don't know if you found anyone yet, but most people I know of doing circular printing are going to want to supply their own mugs. As a matter of fact, most people like to supply their own anything when producing this sort of product.
If they break some or have misprints.... how are they going to replace your merchandise ??
Ah makes sense. But I sure i could work something out. These are available at the 99Cent store. So i'm not that concern about a vendor breaking a few. I'm still searching, shipping on these mugs kills the price. It would cost about $150-200 just for shipping.
You're still going to have a shipping problem. He's up my way and doesn't deliver on a timely basis. So, you'd need to get them there and then pick them up if you don't want to pay shipping charges for breakables.
I'll call him later and if he's interested, I'll PM his information to you.