Marakanetz:
You're right, but the larger breakers typically have better contact and I've been told are quieter. I don't know if that's true--but it really doesn't cost any more, and there's no harm in it. Keep in mind there's another 220v breaker back at the panel--that's why it's okay to have 4 20amp circuits on a 60amp incoming source--and it's unlikely you'll trip that because you will never (as you pointed out) use anywhere close to the 20amps on source components.
You're right, but the larger breakers typically have better contact and I've been told are quieter. I don't know if that's true--but it really doesn't cost any more, and there's no harm in it. Keep in mind there's another 220v breaker back at the panel--that's why it's okay to have 4 20amp circuits on a 60amp incoming source--and it's unlikely you'll trip that because you will never (as you pointed out) use anywhere close to the 20amps on source components.