I'm not sure if its exactly what you are looking for, but are you talking about, but do you want a thing that you either light or pull something, and it explodes c******i all over the place?
I hate to admit it, but the OTHER wedding website with the same name as the papery stuff sells bazookas in their party shop.
Also, Forever After sells table torpedoes
http://www.foreverafter.co.uk/shopping/index.htm
Just had a quick look, but I hope that helps!
Dxx