Would you care to share the 'better' advice here ?, it may be of some use to someone else.
Synths to complement existing ones:
Moog Sub 37
Yamaha 01v96i digital mixer/audio interface/daw control
Neumann KH 120
Beyerdynamic DT-770 Pro 32 Ohm
Eventide Eclipse or Valhalla Plugins
Sennheiser MKH 416-P48U3
Cubase AI (free license with yamaha 01v96i) or Protools
You seem to have a quite big budget.
From what I have heard the Eventide Eclipse does not come close to the H8000FW.
The price point is very tempting but the sound quality is not nearly as good and not as good converters which probably is the main reason.
Do not believe the marketing on this one, all pros who compare with the H8000FW says the same really..
Anyway try it out, I am sure you can find it cheap used somewhere if you are not happy with it there is plenty of other alternatives..
I have not heard the DT770, but I would not recommend for instance my DT880 for ambient, if they have similar problem with the high frequencies. I am on the hunt for new headphones myself..but it is hard.. to find the perfect phones..
I think it is about personal preference, and how pure you want your sound chain, personally mixing high end gear with budget mixers I would be careful about, I have heard good things about the Yamaha 01v96i great bang for the buck and motorized faders etc.. are you going to use it only as a digital mixer ?
I understand you are going to use the Yamaha 01v96i as your monitor controller also, this is a very important part of the chain, different monitor controllers can make speakers sounds like new speakers as it did for me when switching from Dangerous audio Source to Antelope Audio Eclipse so yeah.. please consider that, try to think long term.
You might want to look into the new SSL Sigma digitally controlled analogue mixer and monitor controller.
It cost slightly more then your Yamaha but it is worth the money for sure, this is maybe one of the first time you can get a mixer with the sound of an high end console in this price range.
The whole idea with this, it is an analogue mixer inside of this box, but you can control it through your computer in your DAW you will still change the volume the Analogue way NOT the digital way since it is an analogue summing mixer. Well just some ideas... to consider in your sound chain... since you want to use a mixer... You can buy for instance the upcoming Behringer X-toch or X -Touch compact with motorized faders and to control the Sigma through midi, you will now have the sound of en Expensive SSL console for not much more then what you would pay for the Yamaha mixer plus a probably a a lot better monitor controller and monitor output.
Well so many things to consider... so many solutions ... I just giving you some ideas...