I have the '08 111 and weigh 79 kg and love to use my 6.6 Maui Sails TR-4 (7.6 is the sweet spot for the 111).
Someone with a 122 will probably give you a better answer, but I would say that the 7.0 is a little on the small side, but usable. What I mean is that to be fully powerd on the 7.0 you will likely be in 17-20 knot winds. The 122 will be a rough, demanding ride if you are in open water in these condition, but if you are in protected flat water, the 7.0 should work fine.
For the new iS boards, the suggested sail ranges are pretty broad including a 6.0 for the 122. I once used a 5.7 on my 111 in flat water, which worked, but it was really too small.