it depends on your BB size is it 30mm or 24mm , i have been curious about this look bike i saw on hambini's channel that had a massive spindle ,
i personally like sram force or sram red , but you need and adapter for gxp , i can always find a used one for a decent price and they add stiffness where it counts , i only use alloy cranks on my commuters or cross/gravel trainers , but if i can find a carbon crank i would go for that any day over the mushy feeling of an alloy ,
but maybe you can find a dura-ace that would be a direct branch on the upgrade tree ,
i hear the cannondale hollow grams cranks are the shizznit ,
they always seem to be really expensive even without a power meter ,
105 is ok too ,
i really just look to add stiffness that adds responsiveness and efficiency rather than just weight savings maybe try better wheels and tires too
