That is the one with a single foot (SF) and a dual V belt pulley (DV). That's not what you want. Yanmar engines have the dual foot configuration. You should see it clearly when you examine your existing alternator. The XT-DF-170-J10 has the footprint you need and the J10 pulley is a better selection. I think if you want the XT model, you will be committed to converting your entire pulley system. With that size, a single v-belt will wear out belts quickly and leave a mess of belt dust inside your engine compartment. If you don't want to change your pulley system, then I think you need to consider the 6-Series alternators.
My previous owner installed a 125 amp alternator and used the OEM v-belt pulley system. Belt dust created a huge mess. I bought the kit for installing the J10 pulleys and it wasn't a hard job doing the conversion but I did have to buy an expensive prop puller to get the main drive pulley off. So far, it's been a 1-time use out of that tool, but at least I have it for future use

. I'm glad I made the conversion because any future alternator purchase won't be limited to one with a v-belt. The serpentine belt is a big improvement. I agree that the belt buddy is also a good improvement to get the proper belt tension. Everything we are talking about requires money spent in a cascading series of improvements. It's pretty much unavoidable. When you make a decision to use your boat in a certain way that leaves you more vulnerable to weaknesses that can lead to trouble, you have to be aware that there will be cost consequences. If you tether your boat to a dock, you can get by with far less ...
When you read about the experiences of sailors who leave the dock behind, you will realize that refitting the boat is a significant project with significant costs.