I need help with my tophat!!

Hi people! This is my first blog about the upcoming Ozine fest '09. *applause* Well, anyway, my friend Umi and I are going to cosplay Ciel Phantomhive (Yes, both of us are cosplaying him) during that convention and I am totally excited! Yahoo! We're giving the character a twist of our originality. We already have patterns for our costumes and the two costumes are already in progress. However, we still need to make our tophats. I already have the rough idea on how to make one since I've seen a tutorial on Youtube. But I want to make one that's really good. Besides, I'm not sure if the tophat would last long if it were made of poster board and hot glue. So, if ever you know how to make tophats, or if you have a tutorial on how to make tophats, please help me!!!!!!!

Here is the link for the pictures. http://fluffymallows.multiply.com/photos/album/11/Kuroshitsuji_cosplay

The tophats are here:

http://fluffymallows.multiply.com/photos/album/11/Kuroshitsuji_cosplay#3

http://fluffymallows.multiply.com/photos/album/11/Kuroshitsuji_cosplay#6

Also, if you can give me advice as to what materials I should use, that'll be splendid. Thank you!