A good winger (AM R or AM L) will need to have lots or pace and good acceleration. Good dribbling, ball control and crossing are also essential attributes for wingers. With all of the above, your wingers will beat their man and cross the ball from the byline - which are harder to defend than crosses from deep. Here are a few good players I've found.
Theo Walcott (5-stars)
Theo may be a forward, but he plays better on the right wing - a position he played in his early career, for Southampton. He has lightning pace and acceleration with decent dribbling and crossing. He is likely to improve as his career in the game develops.
Nathan Dyer (4-stars)
He is a very similar player to Shaun Wright-Phillips. He is currently on loan at Swansea, but is contracted to Southampton. He is very quick and his other attributes are likely to improve over time. Sign him, if you cannot afford the price-tag of Walcott.