RE: Avistar Props
The Avistar has some problems doing hovers... just not made for it.
If you want to hover... IF it has the ground clearance get an APC 12.25X3.75. That prop will give you the best potential for hovering using a .46. With a O.S. .46 FX, using the APC you can drag 7.5 lbs vertical unlimited. (I haven't tried heavier... I bet it could drag a bit over 8 lbs vertical unlimited.)