I understand the desire to reduce your quiver size and an 8.7 will fit fine between the 11 and 7.2. The down side is that the range of the 11.0 (at least for me) is about 8-13 knots. Other younger, stronger guys can carry an 11.0 to near 20 knots (up wind/down wind - not reaching). At your weight with the 8.7, you will likely plane in 10 knots (a few white caps) with some pumping. At 12 knots, you will not have a problem, so it looks like you may have everything covered if you have steady winds.
Where I live, we have gusty variable winds where I have to choose between being overpowered occasionally or slogging occasionally, but usually its both no matter what I rig.
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.