Designing pottery

[cassa333]

Hi,
The charity I run is going to be running a competition for children to design pictures for crockery.

The winners will have their design printed on different bits of crockewry such as plates and cups etc. and used as a marketing tool later on.

We want to buy in bulk (min 250 items of each) but I can only find one company and that doesn't do the full rang of items.

Can anyone point me in the direction of a good, reliable and reasonably priced crockery printers please.

Thanks

ps It has to be dishwaher and microwave proof.