I value your opinions: 360 Street Setup

I would go with the 270S cam, make sure the 273 rockers don't rub the valve springs or retainers. I would guess that a .060 over 360 would be fine with a stock converter & the gear you have.
A dual plane manifold might be better but a single plane worked fine on my 360; if you find you need more low speed torque try putting a divider in the single plane plenum - under the carb. I've had good luck with Thermoquads.