Agree completely. There's some question as to where he would be asked to play as he doesn't fit with our current formation (which is what, exactly?), but he is definitely talented enough to make it work. We would for sure have to buy at least a right back though, IMO.
Formation-wise, the 4231 like Hustini mentioned would work, provided you don't ask the left and right AM's to play like out-and-out wingers. Keep them near the center of the pitch and let them one-two the defense to death.
Or you could also run a 4-1-2-1-2:
RB - Legro/New CB - Chiello - De Ceglie
Melo/Sissoko
Marchisio/Candreva- Diego
Gourcuff
SS - FW
This formation requires the wing backs to push up and keep possession, so Grygera will not do. Marchisio would be acting as a box to box mid, more defensive in nature, while Diego would be the playmaker. Gourcuff as trequartista. Or we could just say screw it and get Asamoah