Go to this website: http://www.mtechnologies.com/lta/index.htm
Morse Express sells newly manufactured sounders. It is called a KOB (Key on Board). This setup has a sounder and a straight key mounted on a wooden base. It will run off of a battery. You can attach any type of key to this setup if you want to use a different key.
I have purchased old sounders from ebay but you never know if they will work and you can still pay a hefty price for something that might not work.
As far as using the American code or the Continental code, it doesn't matter, the sounder is just a signaling device.