Chevy 350 Twin Turbo Question?

[1987Regal]

In the near future I'm planning on building a twin turbo small block Chev for a 1987 Buick Regal. Now for the questions. I need to know if a good old regular Chev 350 4 bolt main will work for this kind of power or do I need to run an aftermarket block? Next, once I have the block what do I use for internals to withstand this kind of power. I'm looking upwards of about 800 horse. Any advice would be greatly appreciated.

Also....what should I use for turbos? I have seen posts about aftermarket turbos down to turbos of big rigs and turbo pickups.