You will probably have to buy the modules from eBay too. The newer, modern modules won't work in the old FG style radios. Then when you do get the modules, you'll probably need to get them narrow-banded to work with current receivers by one of the radio service centers. Most likely that's why the guy sold them seperately- they had already been narrow-banded.

The buddy box won't need a narrow-band module, just be sure not to turn it on while you're training. Actually, the buddy box might not need a module at all, I'm not sure.

Yea, it's a bit of a hassle to get an FG radio set up for narrow-band use- a little expensive too. But they are high quality radios. I've got four of them.