Hi John
We were at Hunters Moon in June, also been there before. We stayed at Longleat last June. First Hunters Moon, lovely site just pick your pitch carefully. The road can a bit noisy at night, the pitches round to the right back onto a permanent traveller camp so some noise, pitches to the left are all grass so tend to attract the family groups, pitches in the centre are the largest hardstanding ones and in my view the best. Lots to see and do in the area, some lovely walks, shopping etc. Monkeyworld just down the road worth a visit, Tank Museum also very close although we haven't been (not our thing!). There is a pub just down the road, good food but no children allowed in (they were okay with ours 14 and 17 year old though), The Silent Woman. If you want a really superb pub with good value food go to Stoborough, next to Wareham, The Kings Arms.
Longleat is a favourite of ours although we tend to go to visit the Park rather than venture out any further, the site is very large and can be noisy in the school holidays some of the pitches are a tad small but wherever you are you will hear the wolves, lions, sealions at night so be prepared!! As a guest at the site you can walk the grounds at your leisure anytime, we regularly popped down for a game of frisbee next to the house but we did have great weather last time we were there. If you're going for Longleat park preorder your tickets online (there is a saving) and pick up when you arrive. You probably need to allow 2 days just to do the Longleat thing. Like I said last time we were there we only left the site once for a day trip to Bath, although if you need a supermarker there is a large Asda at Frome about 5 miles away.
You will enjoy both sites, we certainly do and love the areas they are in.
Ian