6.5 or 7.5 will be fine...
With the current crop of punchy lipo's a 7.5 would be a safer drive, particularly if your relatively new to things. It won't feel at all slow anywhere really when geared correctly, but should just take the edge of the aggressiveness of a 6.5 and make it feel a little more controllable...that would be my preference anyway.
ESC choice looks fine to me
