Storm with the leather jacket is very 1980s and a possibility.
I wouldn't mind Cyclops with the cowl. Would be something new.
Or maybe the 90s-style cowl with the hair exposed.
-R
The film is set in the 80s. IMO, Cyclops should keep the cowl. He should also get the blue and white X-Factor suit since that was his 80s look.
Jean should go green and gold.
Beast should just be blue trunks.
Wolverine needs the brown suit sine he wore that throughout the 80s up until 1992.
Storm spent most of the 80s with the leather and mohawk look. She needs it back.
Magneto doesn't need a comic accurate costume but in the 80s, he wore purple and black and went helmetless. I'd like to see a throwback to that.
Apocalypse just needs to go with the blue and silver armored look.
Archangel should go with his Fall of the Mutants costume since that story is the one being adapted anyway + it's his most iconic.
The age of Cyclop's and Jean's actors makes me think that the next film is going to be set in the late 1980s instead of the 90s, in which case I'm hoping that X7 is set in 1987 or 1988 Storm would get her black and gold Inferno costume, Cyclops would retain his costume but go hoodless, Jean would switch to red and yellow or green and white with a big X across the chest, Beast would switch to a red and black bodysuit and Wolverine would look the same. Gambit and Bishop would join the team. Since Kinberg said that DOFP was indeed a reboot and characters may be born earlier, I'd also introduce Iceman, Rogue, Colossus and Shadowcat as younger students who are around 14-17 while Scott, Jean and Ororo will have graduated and be around 20-21.
Fox gave us accurate 60s costumes in First Class. I really hope they borrow the 80s looks for Apocalypse and the film afterwards.
X8 can go with the Jim Lee Costumes and change Wolverine to his yellow and blue costume.