When I try to put a signal chain together, I consider all the OD/Distortion/Fuzz effects as 'part of the amp' and put them last in line to the amp's input. Everything else, especially the time mod stuff (chorus, phase, flange wahwah - except for maybe volume pedal and delay unit) go before everything else - just as if it was just the amp and a wah. I mostly use the simplified Hendrix model, guitar > wah > fuzz > amp because with distortion before time mod, the sound gets rather nasty and nasally.
You still might try the MetalZone though; it has some pretty active mid level and frequency controls that allow a real scooped sound if you need it. I don't use mine much now, but for awhile there I considered it my 'Boogie in a Box' and it went last in the chain, right before the amp and after the rest of my pedalboard. With the MZ (or other high gain type distortion device) you effectively wind up with two different sounding amps, more or less.