RE: what size prop should i use to fly?
Another prop that I have had good luck with is the Evolution series props. I have used a Evolution 10x6 on my Thunder Tiger Pro .46 and it would haul my Tower Trainer vertical from the ground to at least a couple hundred feet. I was really impressed with this combo. Only downside I have seen with the Evolution props is that they are not balanced well from the factory but with a little paitience they turn out to be very good props.