The special move set is better overall, but I use a physical Tapu Koko with the following stats.
Tapu Koko @ Life Orb/Terrain Extender
Ability: Electric Surge
Nature: Jolly (+Speed, -Special Attack)
EV Spread: 252 Attack, 252 Speed, 4 Special Defense
Wild Charge is your only STAB and effectively deals double damage due to STAB and Electric Terrain being active. Brave Bird takes care of the Grass types that resist your STAB. U-turn is for momentum. The final slot is for Roost so you can regain your health from the recoil damage, preferably on a switch.
The item is interchangeable, but I have used Life Orb more frequently. Choice Band/Scarf would be a good substitute, most likely switching Roost for Steel Wing for additional coverage against Rock types.