Kit Rae lists what he thinks are good clones here.
The Big Muff History of All Versions - Sovtek Big Muffs
I have a few originals from the era - a v6 Civil War, a Tall Font and a Bubble.
In order to get them to work in a mix, you really do need a mids boost on a modern muff. Only really the Civil War manages to kinda cut through because it's the least scooped of the three.
my favorite modern production muffs are the Broughton Pi (based on my personal favorite bubble font muff with the most crushing low end I have ever heard); COG Effects Grand Tarkin (more Civil War based than tall font but we are splitting hairs here); and the Stomp Under Foot Civil Unrest.
I would not buy a modern muff without a mids dial. And I am sorry but JHS continues and probably always will turn my stomach.