We have stayed several times at this site:
http://www.southlytchettmanor.co.uk/
It is near to Poole Harbour
, with all it's many attractions and days out available 
, plus its well-organised & very friendly 
. I have spoken with the proprietors, who are very keen to accomodate a rally like ours
, but sadly their 'no-go for rallies' period 
is - yes, July & August 
!If you have no joy elsewhere for July, then these people would love to see us during June or September.
Keep up the good work,
Paul