well the guy in youtube could have a saito 150 under the cowl... you never know. Its essential you choose a pitch of minimum 6 or 7 fot this application. just buy a suitable 2 blade, 3 blade and 4 blade props. try them and see for yourself.

I recommend you start with a 2 blade 15x8 or 14x10.

then you can try Master Airscrew's 3 blade prop: 14x9

then you can see if you want to go for 4 blade.. most probably a 13x10 if there is such a 4 blade prop.