There's an Essex boy related to southampton uni paintball club going so there's a good chance of some going from that way
Camping is available, there is usually plenty of space in the allocated area but postal ask that anyone planning to camp to message or email them so that they can gauge that there is space
(Which reminds me I don't think I have told them yet this time)
Last years camping spot has some firm areas, but is walled and sheltered well from any weather. So I would recommend getting some pegs for hard ground and bring a decent mallet/hammer, and a tent that is not necessarily pop up but self standing so if you don't get one one the best spots you can at least get some strategic pegs down to secure