Try Tresseck in Herefordshire - right up your street by sound of it - real camping, next to pub and river, what more could you want! Their web site looks lovely. Have a great time wherever you go.
Don't forget to leave a review of the campsites you have visited this year or last!
The Hollybush near Hay on Wye is right next to the river (plus you can hire canoes from them) and has a pub. They're happy to take group bookings and you can light campfires. A great, laid back site!