Big roller cams rule, but it sounds like your leaning towards the flat tappet route.
I had a simlar set up as you in my 74 Nova 468 BBC - I ran a CC hydralic flat tappet 305 Magnum, it had a nasty idle, great throttle response and pulled like the dickens well past my comfort zone.
I mostly drag raced this car but it did see the ocassional trip to the parts house or to a Sonic drive-thru.
It was well mannered and I wouldn't be afraid to run it in a street car.
On a side note:
I tried a bracket master II camshaft just for $hits and giggles, slowed my car, 3 weekends later I had rolled 3 lobes which might have been my problem to begin with, dunno? I do know my wallet was a tad lighter.
I stuck the 305 magnum back in and it was till in the motor 3 years later when I sold the car.
Cp