You might want to consider something that protects up underneath the chin as well. It's pretty much a sure bet that shots have a way of deflecting up into the underside of your chin. Throat protection is something I don't mess around with.....
The tricky issue here is that this can impede movement quite a bit. Most things that give that much coverage tend to also prevent standing in guards such as Ochs or high vom Tag.
David Teague made me an *awesome* mail standard that has a trauma plate underneath. I love it. Basically, he took a rivetted mail standard from IceFalcon, put it on thick padding, and sewed a hardened plate in between the mail and the padding where the throat is. The result is something that protects the throat incredibly well, fans out to protects the collar bones pretty well, and is flexible enough that I can lift my arms straight up without even really noticing that it is on. The downside is that he made this as a favor (though I paid for the mail), and he doesn't make this commercially. Still, if you ever want to consider a do-it-yourself project, this one would be a great one.