Alexis Sanchez would be worth a punt (although I admit not having seen him play before the world cup). I think buying a quality right winger would most benifit our first team, rather than a centre forward who would just be shoved on the wing at some point and ruined anyway.
Ozil would be a good buy to play in an attacking midfield role and given freedom to roam, but I can't imagine him being nearly as effective as he was during the World Cup against good league opposition and in Europe, where he won't be afforded so much space.