550hp with a single charger is doable, but you're going to be giving up a lot in terms of drivability.
With your lift and MT/Rs, you're not going to like a smoky, laggy truck with no bottom end. I've heard of full B1s being pushed to 58psi, and after that, they're pretty much off the map.
If you're looking for more HP, you're going to have to swap injectors anyway.
I guess what I'm saying is that I'd shoot for a little less HP, keep the injectors and box you have now, just give yourself enough air for the DD3s/BC combo. A KSB-1 will spool enough to live with and should give you enough air to burn what you have. 450Hp is a lot and doable with a single. 550Hp is generally past the point of diminishing returns in the real world.
Justin