Scott, I recommend B & H Photo online. Go to bhphotovideo,com and search headset & earset microphones and browse for what you need. You may also find an adapter for your XLR under Pro Audio accessories, if needed, on the same site. I buy from these guys all the time and their prices and shipping are the best.

http://www.bhphotovideo.com/c/search?sts=ta&Ns=p_POPULARITY%7c1&N=0&srtclk=sort&Ntt=headset+%26+earset+microphones