Prop Propeller Selection

[corsair_pilot]

I know I'm a while off needing this, but trying to work out the parts i'm going to need to build my plane. I'm wanting to build a Corsair with a wingspan between 1.5 - 2m.
How do i work out what size propeller I need? I'm guessing part of it depends on what motor i'm going to run as well?

 

[corsair_pilot]

I was thinking I would like to do maybe a 1/6th scale. That makes my wingspan 2.08M. Is there any point sticking to a standard scale like going to go to a 1/5 or 1/8 scale?
Trying to work out a nice motor combo to go with this, I'm keeping it electric as I can't afford the 5k to get a nice radial engine..... yet