need help putting a bracket SBC combo together

[ProStreet68SB]

so i've decided that i'd like to put together a nice bracket motor than will have plenty of street duty also, i'll give my thoughts on what i have so far, bare in mind i havent bought anything but my block so far so things can be made to work. i'd like it to run on pump gas (91)
My block is a 350 2-bolt main block
4-bolt splayed mains ( whats good and whats not in this area?)
eagle forged stroker rotating assembly with h-beam rods and flat tops ( the rebuild kit that is)
I'd like to get a set of Trick Flow heads, was looking at their 75cc heads (def open to suggestions though)
Cam- yet to be determined maybe you guys can help me out here.( would like a solid roller since it's a bracket motor)
intake- still havent figured it out
carb- like to run a quadra jet just to be a little different, but want it to work with nitrous too.
and last but not least, nitrous, i want to be able to run a 200shot of nitrous, but from ZEXs website i cant run that without running race gas, why is that?
if i'm missing anything let me know, or any suggestions i'm very open and willing to learn person, looking for about 425-475 before nitrous and i'll be happy. sorry for the long post.

Thanks,
Nick