RE: GP Spacewalker prop
Go with the guys , the 14x6 is perfect. If you go with the x7 or x8 you will not do those perfect landings the SW is famous for.
You can break it with the 14x6 , if you want to be extra carefull use a 13x6 for the first few tanks but not really necessary. If you really love your SW do the run in on a test stand.......