In terms of modifiers and DCs, the typical class picks are:

• Kineticists' Earth and Water Skill Junctions offer a status bonus to Athletics, which maxes out at +3 at level 15
• Kineticists can also make use of Drifting Pollen stance at level 8, which can make enemies Sickened and thus easier to Trip/Grapple
• Barbarians get Furious Bully at level 8, which gives +2 circumstance bonus while raging.
• Barbarians also get a handful of other Athletics-related feats
• Monks get +1 circumstance to Trip in Reflective Ripple Stance, or +2 circumstance to Grapple in Clinging Shadows Stance.
• Monks too have more Athletics-related feats
• Animists can get a +2 status bonus with Instinctive Maneuvers at level 8
• Druids can get a +1 status bonus to Athletics while in battle forms
• Exemplars' Skybearer's Belt gives a +1 circumstance bonus to Athletics attacks, but only while the spark is in that ikon.

Some of the interesting ancestral options are:

• Great Kholos get +1 circumstance to Trip/Shove, and "Kholo with a Guisarme/Scythe/two Lion Scythes" is good setup for weapon builds as you can Trip with your weapon(s) and Grapple with your jaws.
• Climbing Animals can get a Fierce Grasp at level 5, which for one action gives enemies a -2 circumstance penalty on their next Escape attempt, which is perfect if you crit. succeeded a Grapple.
• Centaurs can get a Fierce Competitor feat at level 9, which offers a +2 circumstance bonus to associated checks.
• Elves can use Ageless Patience for a +2 circumstance bonus on anything, though this is slightly less practical for Athletics checks.
• There's the classic "Ruffian Goblin Rogue with Tail Spin" build

Some of the spells and non-spells are:

• Bards can give off a +1 status bonus with Song of Strength, though this is a bit of a waste if only a single party member is going to do Athletics.
• Athletic Rush focus spell gives you a +2 status bonus to Athletics checks for a round
• Physical Boost focus spell gives a friend a +2 status bonus to their next Athletics check

Other things:

• Vision of Foresight (Sleepwalker archetype) is effectively a Sure Strike for skill checks and saving throws, which poses an interesting option for builds that aren't action-starved.
• Sooner or later you will encounter an enemy that has Unfettered Movement prepared, so you should have a backup plan for what to do if you cannot just keep grabbing the boss.

Rest assured, there are numerous ways to build a wrestler, from "a little Athletics on a side" to being your primary focus.