Hi there
Try a look at the Camping & Caravan club site at Moreton. We went a couple of years ago and were very impressed. There is even a train station nearby that takes you into Weymouth.
Cheers
Stessull
We have visited Portasham campsite a few times. It only has a small park for the children but the toilets ect. are spotless and the ground level. We love it there.
I can't recommend East Fleet Highly enough, the new block they have got with showers are fantastic and spotless and our pitches were lovely and flat and very well spaced.
Don't forget to leave a review of the campsites you have visited this year or last!