Thanks for your answers!
My question is mainly about the power output of each engine.
The OS 35AX is of Chinese origin. The Irvine is British. I've had problems with two Made in China OS 55AX engines. They had fuel leaks in the front bearing from the break-in period onwards.
I'd like to use the Irvine since I've never flown with these engines, but it always depends on its power output, as the aircraft is designed for a 40 engine.
The Irvine's manual doesn't specify what propeller it can use, but I think a 10x6 would be fine.