Cosmi is a good choice and I have seen Perugia a few times and they do play some good football
The biggest point that Respaul made imo as per Cosmi is that he brings out the best in his players and that is what is seriously lacking in the Nt at the moment
I do have reservations however for Lippi as Nt manager, he seems to have an ego problem and that is the last thing that the Nt needs right now , another Sacchi who has/had no idea how to deal with big players, so therefore called everyone and his mum to the Nt and Italy just played with average yes men but with no style or pattern. Also Lippi's record against big teams and rival managers is not great and to win Euro2004 and wc 2006, you will have to meet and beat top teams, something Lippi's teams have a problem doing
Del Neri too is a good club manager but do Italy have the palyers to play his brand of football, I mean are there any fast right wingers in Italy at the moment
Vialli may have tapered a bit as a club manager but he has international experience as a player and not too distant, as he probably knows the modern requirement of international football as if Voeller, Hughes and Savicevic can do well, why not Luca
So the probable 2 best candidates are Cosmi and Vialli