I can +1 the Crunch Lab/LiquiFire duo at least. BKP Aftermaths should be great too, probably even better for djent. Still waiting to get mine installed... And I'm sorry for off-topic, but: yeah, developing one's own sound is definetly a top objective for all guitarists, but if I never attempted to mimic great tones like Petrucci or Vai for example, I would have no idea how to achieve any tone. There's no shortcut to knowing what kind of a tone is good or fitting for the job. Sure I could dial a tone that I think is "awesome", but without experience and perspective, I might not be aware that the tone actually sucks balls. This is pretty standard with beginning guitarists, we all know that from some kind of experience. Trying to copy already existing sounds gives you the "building blocks" of tones, and shows them to you in a real context.