Stick with the 10x6.but take an 11x4 and 11x5 with you. I started flying using my CL engine and an 11x4 prop, it was hard getting up to flying speed. There was much more thrust on the 10x6. The 11x4 would get it out of the chocks quick but it didn't have the legs at higher speed.

It's not like you're going to be hovering this thing.