Re: what year and model
Looks like an early '70s Sunray. Can't say for sure, but most likely 60 hp would be max. 30 HP wll be underpowered, 40 hp will give you enough speed for cruising but not enough for skiing. 50 or 60 would be well suited.
It looks like a 14' model. If it is a 16', max maybe 75 hp.