I would encourage you to give more thought to putting the Sniper system on right from the start.
Once you spend $1000-$1500 for a carb, fuel pump, regulator etc, it is hard to justify changing.

Everybody's idea of "good street manners" is different.
That Sniper will really make it nice to drive everyday.

A regular Holley carb or Proform, etc can get the job done. It will just act like a well tuned old school engine/car.
If you do decide to go Holley style carb, I don't like the 850 cfm venturi ratio. Those 950's just work better all around, IMO.

Another thought, for a real nice street driver, put a long collector extension (18" min); before the rest of the exhaust system. For 1500-3000 rpm smooth torque.
Anyway, I think with decent heads and 512 CID it will be a tire frying machine on the street.

Are the Trick Flow heads actually available to buy right now?
I will stay out of the cam discussion. I would end up putting much more duration than most people.... LOL