If building the engine from the crank up, I'd do a strong single turbo. Pick the right combination of pieces, and you can end up with the midrange of a twin turbo, and the simplicity of a single turbo.
Probably the best all-around driveable single turbo we ever built: Yung's 1994 Turbo 3.6.
More torque at 3.000rpm than a 993 Turbo with ECU+exhaust+K16hybrids:
Dyno results, before-and-after: Torque, Horsepower
Over 510ft.lb. and 520hp at the wheels on pump gas.
Who wouldn't be happy with that?!? :-)