I am a Maldon member in Essex and I can strongly recommend the Sussex mob, if you join one of the Sussex clubs £25 a year i think (Buxted, Oaks, Horsham, Swallows or Ford) you can shoot in the SiHFT league.
Or if you just ask them nicely, they may let you shoot as a guest, they are a great bunch of reprobates and we have always been made very welcome at the Sussex clubs.
Somehow I made TEAM ENGLAND 2012 and 2013
Illiterate writer for AirGunner
The real Kung Foo Panda.