Extended CV axles will not do anything for angles. In fact, they will probably not even fit. The reason being, even with a lift the horizontal distance from the differential exit to the wheel hub has not changed all that much with a lift. Only the vertical distance has changed. Yes the overall distance from the differential exit to the wheel hub has increased a little , but not enough for longer axles to fit. Longer cv axles are only for long travel suspensions where the front wheels have been moved out horizontally (3"+) and lifted. The OEM shafts are simply two short for the increased horizontal and vertical distances between the differential exit and wheel hub.
The only way to reduce the angles as a result of a lift is to reduce the lift, lower the differential, or install a long travel kit with the same amount of lift.