If you are able to buy from YAJ you should look for Ayu cell phone straps.
I made my own Ayu A pendant from the metalic A that was hanging from a phone strap of a previous Ayu concert tour.
Like this one, it has an A that can be removed from the strap:
http://page11.auctions.yahoo.co.jp/jp/auction/n68885174
My pendant is the A from the A MUSEUM strap, it's bigger and had rhinestones on it. But this A from the Dome Tour 2001 strap is a good size for a pendant. I know that a few other straps have the A hanging from them, but I can't remember which concert tour they are from.