Duncan,
I would agree with Aimee's suggested site. My wife and I have spent several breaks at Stanwix and have always found it well run. I would say it is much better than the several Haven sites we used to go to when the grandchildren were younger.
We have only visited it either early or late season and the only concern I would have about visiting in high season would be the pitches are a little close together. If you had car, caravan and awning on every pitch I think it might just be a little cramped feeling.
Apparently they have two touring areas but only one is open in low season, not 100% sure about the name but think it might be the Criffel area. Most of the pitches are in small cul de sacs of 6/8 vans, most if not all the pitches are on pea gravel with their own water, waste and electric points. Toilet and shower block always kept clean when we have been there.
The entertainment will be better described on their website. One bar area (upstairs) is adult only. Downstairs is more family orientated. Both have been decorated to a high standard. Small indoor pool, cafe and small shop located in the same building. There is also an outdoor swimming pool. Entrance to the entertainment complex is by pass card only.
The town of Silloth is only a couple of minutes drive away or perhaps a 10 to 15 minute walk. Not a lot in the town to be honest.
Carlisle is about 30 minutes drive, the north end of the lakes about the same.
Good park, we usually go to some of their themed entertainment weekends.We have noticed since we started going about 5 years ago that every winter they seem to upgrade one or other area of the park or entertainment complex. Good to see someone continuing to invest in and develop their facilities.