Have been reading this thread with interest.

Everything these guys are telling you is true.

800hp from a NA small block can be done. At a cost, and with significant compromises!

I'd definitely go the big block route. But even then they can cost big $$.

My 540 with a V7 blower, intercooler and EFI (now in a street driven all steel camaro) made 767ftlb and 852hp on the engine dyno. But it cost me more money than you can shake a hot stick at (as I could not build it myself because I am not a pro). And the engine is full of compromise. People say "for the money you spent on that, it should make 1500 hp". Yes, but for how long?? I want something reliable, and I GENUINELY want to drive it on the street. So everything is over-engineered and relatively un-stressed.

Now this big $$ big block of mine replaces my previous 350 which made a paltry approx 450hp but COULD NOT be driven anywhere near the street without attacting unwanted attention from cops and waking up the grumpy neighbours!!

I don't think anybody here is doubting that you are keen. This is a good trait. But these guys have years of experience, they are telling you something that you need to know. One day you might go on to build a 800hp NA small block, but if/when you do that, I bet you will admit that it was not a simple exercise and you were forced to compromise big time.