J.R.
Hi L.,
the ones I found online were wicked expensive - my advice, go buy a plate that you like... either glass, or ceramic, plain, decorative, whatever you want - just make sure it is oven safe... go buy the ceramic marker that is typically packaged with the signature plate, you can fin it at Hobby Lobby for under 10 bucks - in the paint supplies area.
have people sign the plate, then follow the directions included in the pen pkg, for curing the marker/paint and it will become permanent and dishwasher safe.
our plate turned out great! i got a decorative one from hobby lobby, like a platter really - had a big cupcake on it. soooo cute :)
have fun - congrats on Madeline turning one!!