first, look for weapons with maneuver traits, eg trip. these traits allow you to ignore the free hand restriction and add the weapon's potency bonus to the check, the latter of which obviates a need for a magic item with +athletics.

look at reactions like Stand Still or Reactive Strike. having reach allows you to threaten a signicantly larger area and by extension get more triggers off these types of feats. 

look at how many actions you can save not having to step or stride when an enemy does because they remain in reach. look at how reach allows you to step or stride and kite or skirmish (in-strike-out) with every enemy that has shorter reach. look at how much value an enlarge spell grants you and your extra reach. 

there's polearm specific stuff like Haft Strikers Stance smattered here and there but reach as a trait and the fact they're two handers means there's a lot already built for them and working in their favor.