RE: Propellers
Don't forget Grish Tornados!
As for Cox props, it's a real pain finding them online and knowing if they are going to break or not. It used to be that when you bought a Cox prop it was truly flexible. I don't know if it was a change in resin or just age affecting old stock, but they definitely aren't the Cox props I remember as a 'Ute.
....As cheap as they are, it's probably best to stock up while you can, when you can.