Mouthpiece for a Conn 8D

I currently am the proud owner of a Conn 8DS, but I have a question: What mouthpiece would be best to use with it? I have two mouthpieces right now: a Giardinelli C8 (which I've had since I started playing in 5th grade) and a Conn 7BW (which came with the horn and I haven't even opened). I am not opposed to buying a new mouthpiece, but if one I already have is good, I'll stick with that.