A lot of pickups will get you there; Hetfield played mostly midrangey mahogany guitars throughout his career, so you really need to look for one that will make your basswood Ibanez with its super-thin bolt-on neck sound more like his typical Explorer/LesPauls.
Putting a EMG Het set into the RG might sound good, but it will not sound like a mahogany explorer with the same pickups.
I think you'll fare better with something fuller sounding, such as a Nailbomb or Miracle Man.
One more thing
For me THE Hetfield sound is the Master of Puppets sound and that was an Explorer (I think) with a Seymour Duncan Invader (not an EMG, this is for sure) into a Mesa Boogie preamp (IIc?) slaved into a Marshall power amp. In other words, it was neither Rectifiert nor EMGs back then.
I would not go with "you need {BRANDNAME} gear to sound like him" but really by ears, as to what sounds closer, even if it looks different on paper.
yeah, hard to get that type of tone from a basswood ibanez
Kirk Hammet live les paul tones are hella lot bigger sounding than his superstrats
I wouldn't rule out a ceramic warpig, depending on the amps and pedals
I don't think even the exact same rig would get the master of puppets tone, though
that tone comes a lot from how they recorded and hardly how it must have sounded in person
but a dialed mark III or caliber 50+ through v30s get in the ballpark for sure
in his latest years videos, his tones are pretty much how a diezel sounds without much tweaking
probably mixed with a recto or triaxis, though