Help with rear axle width?

[JustJohn]

Plan on ordering a Moser 12 bolt kit late this summer for a winter project so this gives me the opportunity to change the axle width.

I don't have any issues with decent adapters to fix my offset but am I better off just asking for a custom axle width, which would let me run high offset wheels? This is already a wide rear end on a 69 Impala and I plan on fitting C6 Corvette wheels.

Also, what's the current state of debate on clutch vs gear driven limited slip? The cost difference isn't that much and this is a street driven car.