The Isabella ones ARE FOR a full awning. They work just as well if not better than one that goes right over and they put any stress in the correct place, not across the centre of the poles. The ones that you mention can chaff the awning fabric and in windy coniditions flap and vibrate all night. They use the same size of ground peg too, so I can only see advantages.
With the Isabella method, you are using two straps, not one, but still only two pegs. Win win as far as I can see.
As far as recommendations, they are all pretty much the same thing unless your specific awning has proper points on it, in which case a recommendation is pointless as you would need to use the manufacturers own.