There is a very limited range of choices for folding prop blades. Of the ones I tested, the Cam 9×5’s performed the best. See the thread “SR 190 Battery Test” for data using a 4.8 volt IPS motor with 4:1 gearing. There is data for both non-folding and folders. The Cam 9×5 performed about the same as a GWS slowfly (orange) 8×6 non-folder regarding propulsive power.
All the above data was taken using a SR 190 nicad battery. As you know, this battery is now obsolete. We are currently using KAN 400 NiMH batteries, which are slightly lighter, give a little more power, and are much cheaper.