The hinge trigger is still in the works (but Jon Bon is very busy at the moment!) as are some other interesting trigger options that I can't tell you about without killing you shortly after
If you go and look at my report on Amsterdam on
www.warpig.com you will also find a pic of a prototype of some of the new Sovereign stuff coming out. It looks good!
You can get swing triggers from a place in America called Maxx Paintball, the airsmith is a great guy called Brad who does some stunning work. But since you are in the UK you may want to wait for the stuff from Arrow Precision.
I actually just sold my Sov II (an american offered me too much $$$ to refuse

) but will be getting one of the new ones with swing trigger I expect.
If you are interested I know of a set of BOA barrels in different bores for the Sov...
manike