A (solar) kytoon has double lift: a kite lift, benefiting from strong winds at high altitude, and an aerostatic lift (about 1 N / m³ (= 0.1 kg / m³) or 1.5 N / m³ and more if no wind = less loss by convection or/and high insulation) when the black part is well insulated by a transparent envelope like this:
Thin film solar panels can weight about 0.5 kg / m². And this technology is progressing, going toward 0.08 kg / m².
Perhaps the kite alone could be sufficient, the thin film solar cells being implemented on the wings.