2 Gyms in West Sussex for you.

Gym Xtreme in Worthing.
Knocks Gym - Rustington.

Both great facilities and good classes.
Ive just started teaching NoGi at both, Monday nights in Worthing and Friday nights in Rustington. Lots of other instructors all covering different styles.

Both have good matted areas, boxing rings, lots of bags, conditioning / weights etc
Worthing has a cage also, Rustington getting cage wall fitted soon.

If you're in West Sussex, both are well worth checking out.