I think it is a big jump going from the 125 rocket down to the iS 86, so just looking at your "quiver" of boards, the F93 seems to fit better. However, a lot depends on your typical wind conditions. If you have a lot of very windy days (over 25 knots), the 86 may be a good choice. If most of your days are under 25 knots, then the 93 would be a better choice.
As for sails, the answer is similar to the boards, what are your typical wind conditions? A 4.0-4.5 sail may be a good addition if you have a lot of 25 knot + days iS86). Or a 6.0-6.3 would be a good addition if most of your days are under 25 knots (F93).
I have a small Tiga with 80+ liters of volume, but I don't use it much because of the gusty conditions I sail in. It sinks quickly in the holes and lulls so I prefer a 105 liter board which is a little too big in 25 knot+ winds, but I don't fall off or sink in the holes and wind shadows. I weight 78 kg. I was out on my 105L HiFly last week in winds gusting to 28-30 knots with a 4.5 sail. Most of the time, it was great fun, but in the gusts, I had to sheet out and hang on for 10-30 seconds, then back to controlled sailing.
I have an iS 111, but no experience with the 86. The iSonics are a bit technical to sail and take a while to get dialed in and comfortable. The Futuras should be more comfortable to sail from the beginning and probably a much smoother ride.
I hope this helps with your decision.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.