Silpat is great to work with, have not used the other. Try to price out before you buy, you'd be suprised what some folks over charge.
The price should be between 15 and 30 dollars US.
Here is the page for Bigtray,
http://www.bigtray.com/productlist.asp!catid.14880.html
and the page for bridgekitchenware
http://bridgekitchenware.com/cgi-bin/scodb.cgi
I think this question is a matter of budget, both products look to be great ones.
