Unlike vintage pedals old rack gear is mostly a "worst of both worlds" scenario compared to modern gear - it's generally harder to use, less reliable and there's very few cases where it sounds better. Trying to program sounds on an old Eventide or Lexicon is incredibly tedious if you're used to Axe-Edit, and the stuff like the Synergy modules will get you a lot of the old rack pres with way more flexibility.
Having said that, here's some of my favourites!
Preamps
Triaxis (you've got this covered)
Boogie Studio Pre (Syn IICP would cover this)
ADA MP-1
Peavey Rockmaster (Syn 5150 is similar)
I think the Synergy 800 module sounds way more like a classic Marshall than a JMP1 but let's put the JMP1 in "classic" territory for to the number of bands that used them.
Classic Effects that are all expensive AF now
TC2290 - Fractal 2290 sounds identical
Roland SDE 1000/3000 - EVH approved, but you need 2 for stereo and they're huge
Lexicon PCM70 - Again we have the Circular/Pan delays in the Axe. Rich Plate and Concert Hall reverb are pretty great though
Roland Dimension D - world's second most expensive chorus
Dytronics TriChorus - world's most expensive chorus
Eventide H3000 - sounds beautiful but you could buy an Axe-Fx and take your family or to a Michelin starred restaurant for the price they go for used now
Underrated effects that are more reasonable and kinda fun
Yamaha SPX90/900/FX900
Roland DEP-5
Alesis Quadraverb
Korg A3
Sony DPS M7/R7
Lexicon MPX-1
Kurzweil Rumor
Digitech TRS-24
Roland GP100
I've got in depth videos with all these (except the Tri Chorus) on my channel if you want to hear what they do. Or grab my blocks library for recreations of them all and save yourself the trauma