Hi Lizzy, if you have sailed cambered sails before and don't mind using them the formula experience will work better in lower wind speeds to get you planning earlier and they will keep you going through the lulls but will be heavier, less fun when not planning, a lot harder to rig and not so fun when turning round. A no cam sail will be a lot lighter and easier to rig and turn. At your weight I don't think you will see much gain over a slightly smaller rig i.e. a 7.5m
If you want to go the cam route then try to source a twin cam, much more user friendly!
2016 Severne Blade 4.0, 4.5 & 5.0, 2012 Neil Pryde Firefly 5.3, 5.7 & 6.1, 2016 Severne NCX 7.0 & 8.0, 2014 Severne Overdrives 7.0, 7.8, 8.6 & 9.5
2017 Ultrakode 93, 2016 Flare 103L, 2015 isonic 107 & 120, 2016 AtomIQ 114 & 2014 Starboard Ultrasonic 147