Fekir sounds like a great option from his stats, can Pep improve him, if he has the intelligence to take on board how Pep's teams play then he could be good shout. However he appears to be of a front two option, to replace either Jesus or Aguero, whereas Sanchez is an alternative to either Sane, or Sterling but could also play central or "false 9" as required, AND he has premier league experience. If we can't get Sanchez for 30 million or less then Fekir could be a more likely signing for January and then sign Sanchez for free in summer.
I still would like to see us sign a center back, Mangala doesn't fill me with confidence, Kompany will barely play, and that leaves us with Stones and Otamendi, if one receives an injury before a Champions League match or League Cup final, then we will be down to the bare bones again. Pep said we will buy for the long term which should rule out JFE.
Inigo Martinez and Sanchez should be the minimum requirements in this window. Pep liked to have a small core squad to work with supplemented by kids, he soon realised we needed a couple of players adding to this to compete for all four trophies, and personally I think we need about 18/19 potential first teamers to cover injuries through the season too. We have had Stones, Mendy, Silva, now Jesus missing for long periods of this season. Kompany cannot play more than 3 games at a time, and KDB has either been sick or looks tired due to the amount of games he is currently playing.