If you are looking for a 'take it to the next level' kind of flight experience, a prop change isn't usually what will give you that. I've never been one to fiddle with different props, trying to find the perfect one, because when you are dealing with a brushed motor, power is limited and a tweak doesn't do much. I've tried that in the past when someone recommended, "Hey, try the X x Y prop on your plane and see the difference!" Not much, if any difference.

The props that GWS recommends for their motor/gearbox/battery combination are pretty well bang on.

What kind of battery are you using? If you are looking for a change, and you are using a cheap, small battery, a jump to a good quality 9.6V battery should give you a bit more performance. Or, take the plunge and get an inexpensive brushless motor. You'd be amazed at what a cheap $10 brushless motor & a 3S lipo will do to your tame little plane.