[WSSix]

You're talking engine power goals not rear wheel goals, correct?

Pro-chargers whine a lot are are better suited for a drag race situation. They need RPMs to produce their power. They make great power though.

Have you considered Magnacharger, Kenne Bell, or Whipple? I know Magnacharger makes their kits to fit the factory accessory brackets. I'm sure the other two do as well. You could also do a simple heads change to lower your compression if you want that much boost. However, I've built a few C5 vettes using a Manacharger, stock CC size heads but ported, a cam, and the other needed parts like exhaust and intake and have easily met your goals while producing instant torque. They were more fun to drive than the Pro-charged C5 Z06 I built that had slightly higher peak power numbers.

My vote is for a drop out. There are so many little items you'll need. Whatever you don't use you can sale or trade for what you need. The factory LSx computers, both Gen 3 and 4, can register boost up to 2 and 3 bar respectively. I believe those are the correct numbers. The factory intakes work just fine for your power levels should you go turbo or Pro-charger.

If the drop out is a throttle by wire engine, either make sure the pedal and control module come with the engine or try and leverage for one. It's just more more thing you'll need.

You're not really building anything that exotic so you don't have to get fancy if you don't want to or can't afford to.