Single or Twin turbo setup for 360?

My impression has always been that a compound turbo set-up (a small turbo, blowing into a big turbo, to spool it up) is for a diesel, or for a monster horsepower gasoline engine, over 50 lbs of boost.
A single turbo will easily get you what you want, a twin turbo set-up might be easier to find a kit for, but you will need twice as many turbos,waste gates, Bov's, etc.
Got a buddy making 1200hp with a single turbo on a stroker LS, 500 on a 360 is nothing.