My son uses Ownhammer IRs for Riffing/DJenting and internal IRs for solos. His favorite IR is the Chinese v30 Modern Studio Mix IR: "OwnHammer_412_MAR-CB_V30-CH_SS_Studio-Modern" (I actually like using this one for solos).

I can't even find it on the site any more, but it was a Marshall Checkerbord cabinet with a bunch of speakers.

Look for these four while you're shopping around and you'll have everything you need:

Scumback M75, Chinese V30, G12M-65, and HB-55

Usually the ones with an "SS" in them for solid state power amp work for us.

Once you have the EPSi, you can literally just pick a Treadplate Amp (V or M) from Eleven Rack and play around with it unltil you get something. Maybe a graphic EQ in front or overdrive pedal. Try out the effects for yourself and see what reverbs you like, etc. Get to know it a little as well as try some presets that are already out there.

This one is a Van Halen preset I made for the EPSi, but I always try IRs with it no matter what I'm working on: https://db.tt/T4UJJhug

I originally dialed that up as a way to stack my Maxod oerdrive with the Eleven Rack one, but still works good. I don't use any real overdrive pedals any more with my newer presets, but I think they will depend on your pickups more if the EQs work. But this one is probably my #1 goto preset for VH sounds. From there, you can tweak the amps, ODs, EQs, etc; to get any metal sound.