My personal set up for Boxer:
Epic Iron Helm or Epic Tao Hat
MiniGun (with Epic Iron Helm) or Epic Hunter's Camera
Epic Ice Robe (if you can Skill Cancel well) or Epic Boxer's Trunks
Normal Boxing Glove (since Epic isn't out yet).
Normally, I would increase Defense over Strength if it's a decent Push Type character (to throw them off the cliff). If you're decent with pushing people off the cliff, then increase Defense. Otherwise, if you're the type to just fight them without relying on edging them, Strength will come in handy. Up to you how you want to distribute.
Note, if you choose Epic Helm and Minigun, placing the Minigun first and then using Headbutt will stun them long enough for the Minigun to hit all 10 bullets, redirect them using Epic Ice Robe while they're being hit.