I bought the PSI ones. BUT, I believe Jon Brooks likes the one(s) that come with metric collets. Maybe, it is just about getting the metric collets.
I used my PSI and love it, but haven't come close to what J Brooks has done.
I have a collet chuck and still prefer to make my custom finials on a faceplate. I keep a 1" scrap screwed to the faceplate at all times. I glue on my scrap piece for the finial with CA and turn away. It inly requires about an inch of blank....vs 3-4+ with my collet.
You should also look at the csusa collet....same price range and a higher quality piece imho.
I would buy the beall collet chuck if you want one and expect to get a lot of use out of it. . I had the psi one and it was good especially for the price. I didn't like the big body of it through. Maybe because I'm left handed.
I prefer the beall. The recently departed (from the forum not earth) Andy Little claimed the the different in runout between the two is quite measurable. I never measured and didn't notice a substantial difference.
That said, I make all my finials in my nova pin jaws. I'm too lazy to get my blank down to a nice uniform size for a collet. I just put the blank in the jaws and go.
I wouldn't by a collet chuck set just for this. You likely already have a jacobs chuck for drilling. Glue your cutoff piece to a short piece of 3/8 or 1/2 inch dowel then put the dowel in the jacobs chuck to turn.
You did a nice job of grain matching of the finial to the upper barrel. To me it looks a little long and it was me I would cut the length by at least half.