Hey mate you have LFS for over a year now, don't you already know that there's no such thing?
For what combo do you need a set for? You can have a basic good handling set per car for all tracks and then you just tweak a little the camber, the tyre pressures, the gears and some steering settings and you have a new, fast, but already familiar set to use.
And FYI if the WR is at 100% you can get to 96% with just practice. Then you can gain tops another 1% by the setup and the 3% left is skills and experience.
In my opinion the first thing you should look in a set is if it suits you and if it handles good.
Then you can certainly can go fast with it.