I made this using Goslings peach ginger beer and replaced the lime juice with lemon juice. Loved it a lot, but I would definitely skip the sugar, Goslings is too sweet to add sugar to.

Honestly I avoid adding sugar to most mules/bucks anyway, the only ginger beer I've had that isn't on its own sweet enough to carry these drinks is the sugar free Goslings and I GUESS Fever Tree but even for that one I would use less sugar.