Hi kvda, choosing a new board is always a nice problem to have
Im similar weight/height, 98kg 194cm. For me, iS107 and iS137 works very well. But I do have a Formula 161 as well.
But to be honest, these days I don't use the F161 much because in 8k to 11k I can get going on the iS137 with my 9.5m and 51cm fin and feel nicely powered.
For me, the iS137 just feels way more exciting c/w formula. If the wind is always under 9/10k, then Formula is easier, and the US147 would be a real option.
If I did not have an F161, then I would probably go US147/iS107 as Im happy to take the 8k to 10k winds as well.
I guess the answer to your question is: If you sail in an area with steady 8k to 11k winds and have a 9.5m race sails, then iS127/137 and a grunty fin will be a best fun/fast. If the winds are less, take the US147.
I understand that the thin hull on the US147 give great control in medium winds, so like the iS127/137, control if the wind pick up will not be a big problem.
Don't rule out the heavy weights iS137, its flat vee to flat hull works great for heavier guys and also allows you run fins down to 45cm in medium/highish winds, and it flys confidently over chop. Today I got over 34k peak with an 8.6m/47cm fin. So it's fast for sure