Your standard 46 2C engine will be happy with an 11x6 for your average sport flying. If you want speed for racing then perhaps a 10x6 or 10x7. For 3D its the 12.25x3.75 or the 11x5.

For me I will go with the TT46, in Malaysia it is the most popular engine for soooooo many years. The 46AX is nice but it is the price that puts me off, the power is not much more than the TT46, I have TT46s that have lasted 5 years and still run good. As for Magnums I met a few guys who had trouble with it. They run fine and after a while there are problems, no real answer as to why but it just has happened too often unlike the TT46 which everyone uses, newbies and the oldies.