I'd only use 1L of brake fluid for a full flush, but if you're doing the clutch too maybe get 1.5L and use a 1-200mL for the clutch and the rest on the brakes. The clutch bleed screw is under the intake manifold kinda, on the front of the gearbox on the slave cylinder. I doubt you'll see a difference in stopping distances, at least on the first stop, it may make a difference at track brake temperatures.