My preference is for a midfielder like Khedira but if Marco Reus is available then we need to do what it takes to get him. Destroyed Zenit last night. And did it from the right wing too which is important as his ability to play both sides would be ideal.
He's the type of player you could play on the left with someone like Theo on the right or he could play on the right with someone like Cazorla on the left and he can adapt his game to give the right balance to the attack in either scenario.
I'm not overly keen on signing a wide player as i think Theo/Wilshere/Gnabry Ozil/Rosicky and Chamberlain/Cazorla is more than good enough for the 3 spots behind the striker but if someone like Reus is possible we should go for it even if it means taking a risk with midfield (probably relying on Wilshere stepping up a level)