No idea on the exhaust, so many choices out there, just have to really hear a muffler on a 3.0 that you like and go with it.
To run a turbo, you'll have to do a LOT of fabrication. You'd need to build custom exhaust headers that combine into a single tube very near the engine (assuming you only want to use a single turbo), weld on a flange for the turbo you'll run, fab tubes from the turbo to the intak manifold, or to an intercooler first, then manifold.
You'd want to run a much bigger throttle body, larger fuel injectors, higher capacity fuel pump, oil/water lines to/from turbo, remapped ECU, depending on the turbo, external wastegate, etc.
You'd not be able to run a very large turbo, as the 3.0 isn't terribly strong. You could give it a 100HP bump and be OK, but a 70 HP bump is more realistic.
No chance of a turbo system from another car even coming close to bolting up. You could scavenge just the turbo, but the rest would still have to be fab'd up.