I just asked the same basic question not more that a couple of weeks ago. Look for the thread "I've Had It"
I purchased the beal because I had major issues with the standard setup. IMHO it was worth the price. Ive turned about a dozen or so pens, chucking up the standard and "B" mandrels. I have also used for my "Dowel" bottle stoppers and a few other things and absolutly recomment getting it. Turning closed end pens, it's a dream come true.
As for where... I've lost the link, but one of our IAP memebers sells the chuck and collets and a significant savings over CSUSA or WoodCraft. I ordered the ER32 collet set from 800Watt on ebay. I probably saved about 40% off of retail, or more.
The only gripe about the chuck is that it is a little difficult to get in close to the chuck itself, But I can live with that.
So if your ready, DO IT!
"Just my opinion, I could be wrong" Dennis Miller