The Powerlyte Scepter is a barrel kit that costs about $100 for 7 bores. It's similar to the Freak in that it uses inserts, however has a better design in which the inserts don't move around (aircompression is used to lock the insert in place). The nice part with it is if you ever switch guns you only need to buy a new back.
All of the barrels that you named are solid barrels. The J&J, Scepter, and Pepperstickz will give you the most bang for your buck though.
I guess they raised the price on them because I got my NIB 7 bore kit for $100 and now it's $130-140. The Empire Revolver is essentially the same kit with 5 bores. If price is bugging you I'd tell you to get the J&J or Pepperstickz, they are cheaper right now and are pretty close in performance.