Before the flat top receivers became the new norm, there were better choices for handle mount scopes. Hakko made such a 4X IR scope for Colt. Today with the move away from the carry handle mounts the scope choices for that configuration are limited, All are Chinese made and the quality can vary widely.
If you must have a carry handle mounted scope, I suggest buying a carry handle scope mount and then mounting a good quality compact 3X or 4X scope on it. If you are on a budget the Nikon P-223 scope for around $125-$150 is a good buy and a good scope for the money.
While the carry handle mounted scope gives free access to the iron sights, the downside is that a scope mounted that high loses more accuracy ( that low mount scopes) at distances other than which it is sighted in at. The other problem is to get proper eye relief and sighting alignment with a handle mounted scope, a cheek rest is a must.