Doing trees that large you are right to want a 24" bar or larger. If I were recommending a saw to handle that size bar I would go with an 80cc size engine or larger, which you have done in the past. To really pull a chain that long you'll want some horsepower, and for that you need displacement. You could do it with a smaller engine but it will be much slower and harder on the saw overall. I don't know if you'll be less tired hoisting less weight for longer or more weight for a shorter period.

The part that I wonder about is why you are going through so many saws. The Husky and Stihls should have lasted you quite a bit especially if you are only doing 6-7 cords a year. Check out how you are running the saws to see if you can change something to have them last longer.

Husky 359 is 59cc
Husky 357XP is 56.5cc

Shindaiwa 757 is 73.5cc

Based on he engine sizes I would go with the Shinny. I have never run a Shinny but I think I have read they are a decent saw.

Dolmar/Makita makes a 7900/7901 that is a very nice saw. Another one to consider. They do not have the best parts support but their support is better than Shinny. But then again I have never had need to look for Shinny parts, I've just not seen them advertised.

You might be better off sticking with what local dealer support you have. Husky and Stihl are likely your best bets from that perspective.

By far you best bang for for the buck is going to be the Makits DCS6401. Goes for $500 new from Bailys. Takes up to a 28/32 inch bar, and has optional big bore kit to convert it to a monster. Cannot go wrong, this is German stuff.

The most I run on the 6401 is a 20", although if you treat it gentle or are cutting softwood you could go with a 24. I think you'd really want the 80cc version (7900/7901) to run a 28"+ bar. It is one of the best deals out there for a mid/large saw.