The 8.5 Glide on the Futura 122 would see to be about the ultimate early planing 120 liter board.
If you have smaller sails for 14 knots and up, I think the Glide/Futura combination would be very good.
The early Glide 7.5 that I've been sailing gets just about anything going super early.
It's light and has lot's of power and I would expect the newer 8.5 Glide to be similar.
It should be great!
Hope this helps,