I dont recommend cloudlearn unless your child is extremely self disciplined. You may as well just buy the books yourself and contact the exam centre. I wasted a few hundred on it, and my son couldnt get to grips. My friend had the same experience with her daughter. Not structured enough so they just didnt do it.
My dd and ds 1 are doing myonlineschooling.co.uk/ and really enjoying it, but its fairly new, so the classes are tiny, which is a good thing for us as more of teachers attention, but might put others off if they want to use it to socialise too.
Interhigh is supposed to be good too, as is Briteschool