I have an iSonic 111 which isn't too different than the Futura in volume and width. I weigh 78 kg and picked the iS so I could uphaul if the wind drops (which it does a lot where I sail). For me, it is not easy to uphaul, but it's not that difficult either. Foot positioning is critical as either the nose or the tail will sink if I am off 5-10 cm with my feet. At 90 kg, I think you may have a tough time uphauling. It can be done (the deck may go under water slightly), but it will take some practice. Wave action will also make it more difficult. Sail size will play a role too. With my board, a 6.6 is pretty easy to pull up, but my 8.4 is a little more demanding.
You may be better off with the Futura 122, but that all depends on your usual wind conditions, board and sail quivers, skill level, commitment to windsurfing, etc.
Hope this helps.