I'd agree with Faster. You'd get a better ride with some sail up between and working between 45 and 60 degrees. The boat won't roll as much. If you wanted to sail with a reefed main and the engine, that would be a compromise to reefed main and small jib. But I have found the engine to be annoying.
With 8-10 ft seas and 30 knot gusts, the wave period is what is going to decide your optimum speed is...at this point you're sailing the seas (1 at a time) looking for the right combination of comfort and speed. You might want to be heading up ( 45) into the waves and falling off (60) down the backs.
I wouldn't want to pound ( motor ) into these conditions at 25 degrees..for any length of time. My engine wouldn't push 5-6 knots against those waves and winds at that angle.
If you sail close hauled, you're likely to lose boat speed imo..the waves will knock your speed down and they will shadow the wind in the trough. Which is why, you might need to fall off to 60 degrees..on the back of the waves..to maintain boat speed and not bury the bow.