Try Norman and Mary's on the upper Peak Forest.The last boat I bought was moored there and was cheap,isolated with water and toilet disposal.
Can't remember the contact details,but if you pop into TW marine (a short walk away) they will know.It's in the village of Furnessvale just by the railway station.
Just thought,I can give you directions,to the mooring because it is a bugger to find by road.
Through New Mills to Furness Vale.Turn left into Station Road,over the railway crossing,and you will see a farm gate immediately on your right.Go in there and there is a big house at the end of the drive,thats Norman and Mary's house and the mooring is about 500 yards along a track alongside the house.