the best famous branded metal pedals are: mxr dime distortion, krank distortus maximus, ehx metal muff
the mxr sounds a lot like darrell on vulgar display of power, but it's hard to get a deeper tone like on far beyond driven
the krank works great through tubes, especially on the return
but the best distortion pedals i've seen were made by my bandmate, Tiago Zambelli
he made 2 pedals inspired by the dr. boogey pedal, but based on the peavey 5150 e other based on the bogner uberschall circuit
they actually work as solid state preamps, as they have FET gain stages instead of tubes, but using the same architecture of the real amps
tons of gain but they have tube dynamic feel and clarity