Replacement sails - Hood''''s Vektran
You ask, “If you had to pick one of the two sails [mainsail or jib] to replace, which would you do first?”
You say that your mainsail is “of indeterminate age,” but you don’t describe its general condition. Does it show significant signs of wear or damage or patching? I suggest you ask your sailmaker if repairs or reinforcements can be made that will help you get another 2-4 years of service out of it. If you reef early and avoid unintentional or hard jibes, you will reduce the likelihood of damaging it. If so, then I suggest you buy a 130% jib. Your 112% jib is too small to be reasonably competitive in most club racing in light to moderate winds, and replacing it will give you the most improvement in performance. A 130% roller furler will be useful in a wide range of winds, and will maintain reasonably good shape when partially furled. In light air, if other boats are flying 150% genoas, the 130 will be powerful enough to keep you competitive, and within striking range of them, if you can find a little stronger wind or sail a little smarter race or just get a little lucky.
If your sailmaker says the useful life of your mainsail can’t be extended, then you have to replace it first. Take your mainsail to your local sailmaker and show it to him. He can look at your sail and give you better guidance than we can.
I like your idea of using your smaller jib in the stronger winter winds. Depending on your local conditions, it might provide better shape and performance on average than the bigger headsail.
You say your goals are “club racing, durability, and manageable performance for family on roller furler.” I’m no expert on sail design and construction, but I’ve bought a few sails and have raced with the best racing sails as well as the cheapest sails. I don’t believe you need top-of-the-line, hi-tech racing sails to meet your objectives. In most club racing, the skill of the sailor has much more to do with the outcome than the construction of the sails. You can win a lot of club races with a clean bottom and keel and plain dacron sails if you know how to get the most out of them. When the skill level of the competing sailors becomes higher than the norm, then you need the fastest sails to remain competitive. I suggest you buy the best sails that fit your budget. Plain dacron sails made by one of the most reputable sailmakers will be made of excellent quality sailcloth, and will hold their shape and provide good service for a long time. If you can afford to step up a level in quality, you won’t regret it over the long run. Racing sails help you the most in light air and in high winds. They are least important in “average” conditions, in which most races take place.