At 98kg, I'm not the best person to offer you advice. But here something for you think about
Firstly, the iS110 will be an improvement on your iS122. It should have a much bigger usable range than the older iS122, so much so that (with a good selection of fins) it could replace both your iS107 & iS122.
Ideally, you'd be better off with an iS87/107/127 combo, this would be perfect, but as you like to get on your FSW in higher winds I guess you only want to cover mid to light winds for slalom kit.
Having an iS107 and iS122 is a bit of a luxury, and I can't help but feel that if you were to purchase an extra powerful fin for your iS107, it would do the same job as your iS122.
If you have money to spend, then truthfully speaking, at 78kg you would be best with an iS97 (or older iS101) and an iS117. Several lighter guy's are saying that they get no real gain with the iS127 c/w the iS117. The iS97 would enable you comfortably go into slightly higher winds (saving your FSW for proper high winds).
Just my 2 cents worth