I'd cry if we got Downing. He's 27 slow and very average. Saying he'd been an improvement on our Kuyt/Maxi is like saying Lucas is an improvement on Poulsen.
The only available wingers worth considering from the PL are Young and N'zogbia and while both would be represent a significant upgrade, they're not particularly brilliant.
There are a host of talented young wingers across Europe, all of whom have more potential than N'zogbia, and one or two of whom will certainly be the next Messi/Ronaldo.
Players like Turan, Costa, Mata, Hazard, Marin, Payet, Elia, de Federico, Biabiany, Gervinho, Capel etc. Take your pick.
My top 3 choices for the summer are Costa, Hazard and Elia.