Just brainstorming because I don't have the means or knowledge to build something like this.

For the shortblock you could straight up buy a 6.2 Hellcat shortblock from a dealership, but the powdered metal rods might be an issue at your power levels.

The lighter option would be the 6.1 Aluminum block and whatever combination of rotating assembly is the strongest.

Heads the Thiteks would be the top choice, or the 6.4 BGE heads. Hellcat heads have a different intake pattern and I doubt anyone makes a blower manifold.

No clue about which power adder, looking at the charts on the mopar tech archive http://www.moparts.org/Tech/Archive/bb/57.html a 20% 8-71 hitting around 25psi should be there, but I know there is more to it then that.