Super- and turbocharging have become popular enough, nowadays, to create an aftermarket activity in the selling of "blow-thru" modified carbs, and it would seem to me that you could probably use an 850 Holley to good advantage. The vaccum secondary carbs don't work well with boost, so a mechanical-secondary carb such as a "double pumper" is the carb of choice for an application like this. There are some companies that build carbs that are application-specific to "blow thru" that already have the internal modifications made tht are necessary for dealing with boost... that might be worth looking into. Any of these can be used with a "carb hat," or "bonnet" so you don't need a box around them.
Opinions vary, but it seems that most folks think that a compression ratio of not over 9:1 works well for a lot of turbo apps...
TRW Power Forged pistons were available for years as a cheap (but, heavy) alternative to custom ($$$$$$) pistons, but I believe that unless you already have a set, they may not be available in a "forged" configuration any more. I think they changed over to a hypereutectic setup some years back, unfortunately. Those "new" pistons don't have the same desirable characteristics with regard to warding off the potentially disasterous effects of detonation that the earlier forged ones do, unfortunately.
Good luck with your project!!!!