Yes, I would be inclined to re-condition the existing motor or put another Yanmar in there.
A new, different, motor is a lot of work.
For me, my old Volvo MD17C will be replaced with a different motor the next time anything serious happens to it..... perhaps the Beta Marine 40 hp. That is for reasons of astronomical spare parts prices for the Volvo.
Don't re-power with a Volvo. The spare parts prices will choke you. Not at the time. Later. And, believe me, you will choke..