Interchanging sails
This is just my opinion, but I don't think there's enough difference in any of the 25s or 26s to make any difference. I bought a new main for a 25 that I'm running on my 26D and it does fine. It was a lttle off on the measurements but not enough to justify the $200 more to buy a 26D main. The price must be right or you wouldn't ask, so go for it.