If you can find it... try a Taipai 10 X 7. Note: this prop won't fit in a plastic spinner, the root of the blade curves back at the TE and will be almost even with the back of the engine's thrust washer. I used one of these props on a Magnum GP 44 that was running poorly and it nearly doubled the plane's max speed vs using a MA 10 X 6.

There's also the Bolly Clubman props which are 10.5 X or 9.5 X (odd lengths to most people...) Having the 1/2 inch increment on dia will give better ability to fine tune for best performance.

The 10 X 8 probably won't be too far out of line. Try a few different brands... and don't go far from the 10X7.