Raereira,
Unfortunatly I must direct you to the following statement within the Dealers Den rules:
13. Similarly, no items depicting copyrighted characters or trademarks may be sold unless the seller can provide written permission, from the copyright holder, to the convention staff during the convention.
As MLP is copyrightted I'm afraid it would not be possible to sell such items within the Dealers Den unless you have obtained written permission from the copyright holder.
I'm sorry if this has disappointed you and I hope does not tarnish your time at Confuzzled
