#1 Ever Banega
Unai Emery has plenty of experience with Ever Banega. This is due to the fact that Banega played over 200 times for the current Arsenal manager and so, he would be a great fit. Banega won 2 of his 3 Europa League titles with Unai Emery and it is well known that they had a good relationship.
In the past, Arsenal have considered Banega, and with Aaron Ramsey leaving this summer to join Juventus, Banega may actually join the club. However, at 30 he is not a long term option and Unai Emery may be put off by this.
It would be unlikely for Banega to be able to play week in week out in the future. He would, however, be a good short term option perhaps just for a season to improve the squad depth at Arsenal.