depends on what your formation is.
you can play de rossi as central midfielder with side arrow to the left, so you can include all three italian star-midfielders (de rossi, pirlo, gattuso). this gives you stability in the defense.
if you want to have an offensive left-winger, then you could play cassano (who is rather a second striker and more central), del piero (the same, and further too slow) or quagliarella (also rather striker).
there's unfortunately no fitting solution for this positon. in real life it would be di natale, who is at the moment the best italian player of all, but in the game he is seriously underpowered, because of his two-footedness, which takes points away from his other attributes. so he never becomes that great in FM 08.
Hope I could help you