I just picked up a couple of these from Ryan @ Woodturninz.com I really like this design, but I bought the fancy "elite" style that has a gold nib instead of black. It is an easy kit to turn B2B and the center band is just cut to the tube.
The kits are PSI kits but I have had no problems with them myself. They are not on his website, but just give them a call. Ryan has great deals on PSI stuff, I think the bushings were only $3.00
http://www.woodturningz.com/SlimlinePenKits.aspx
Here is one I finished with a lacquer finish a day or two ago.