The BJ4 came out 1st, then the BJ4 worlds edition, I was the UK importer for JConcepts when the BJ4 Worlds was being sold.
The B44 is based around the BJ4 Worlds layout but most parts are differant, there are lots of threads on here about how to fit B44 parts onto the BJ4.
AE have just released the B44.1, this has the new V2 shocks, new top plate, revised slipper, alloy hub, JConcepts body
