Yuuji would have Tiger Stance since nothing else fits and I like the Tiger theme for Yuji. Megumi would have a Beast Eidolon and he'd spec into feats that allow him to fight alongside his shikigami as well.

While I'm here, I might as well do Itafushi. Yuuji is definitely a Monk, maybe with some kind of caster archetype to account for his late manga abilities. Megumi is a summoner that archetypes into rogue.

Geto's Eidolon would be either the Anger Phantom or Devotion Phantom. And he'd definitely have feats that let him fight alongside his curses. Probably lots of summoning spells so he can use multiple curses at once.

Gojo's Conscious Mind would be the Distant Grasp (tho in a perfect world, he'd have both Distant Grasp and Infinite Eye) and his Subconscious Mind would be Precise Discipline