Thanks a lot for the suggestions, guys. I’ve compiled a list, and if I ever “need” another synth, I’ll be going through that list in detail. 
Don’t forget the Waldorg Q, awesome synth with four parts and very easy to navigate and off course the DSI Poly Evolver, also four parts with four sequencers per part! And a knob for each funtion.
Yes, the Waldorf Microwave XT multimode works quite fine and also my Waldorf Q Keyboard has an awesome versatile multimode, even better than either of my Virus. The Q (not micro q) allows a lot of stuff to include Xmorph and layers within even one patch of a multi. The on-board step sequencer on Q allows for poly chord, etc.
Even if you can get a Microwave XT Rack, it’s quite a monster of a true wavetable synth with serious filters and FM abilities and also happens to have one awesome arp. It’s as deep of a synth as Alice’s rabbit hole to Wonderland that keeps on discovering new sonic territories after 14 years and same exact thing with the Q.
The Virus KB and KC I may be looking to let go of one of them because after one has worked with much deeper hardware synths, the limitation of only a few envelopes and LFO’s can make it a task to get it away from “sounding like a Virus”…but they are monster ambient or any genre, as said earlier, I also do not do trance and that silly stereotype about the Virus can be annoying on forums. The effects on Virus, even older Virus, are among the best out there and on par with Analog Four’s Reverb and Delay…except unless you are using a Virus Ti, the earlier Virus only allow you to use either reverb or delay–not both at once…and the effects are limited in the way multimode is done on earlier Virus as well. The Ti does not have that limitation.
Korg Radias can be fine if you can live with it sounding so damn “happy and bright” all the time. I for one only like the drum samples and pretty nice sequencers on the Radias; not as a synth so much.
Novation Supernova 1 (only made as a rack) and Supernova II (both a rack and keys made) has such an awesome arp multimode (8 parts) that it’s really just shy of full blown sequencer and lots of knobs, arp outputs via midi, easy to program, and individual parts of multi audio outs, complete midi specs, and would pick Supernova any day over the Alesis Ion. The Ion does have a great sound engine if you can live with really crappy keys on it…but you get the knobs…trade off.
Hope this helps from my own set-up and rotation.
I’ve never tried a Q, and probably won’t be able to afford one anytime soon. Had an XT for a while, but did not like the multi-mode on it at all. Was basically exactly like that on the Blofeld - a bit too rought to navigate and easy to forget to save patches, if you were working on a few simultaneously. But thanks for the suggestions! The Q Is definitely on the list.
The list so far;
Roland JD800
Prophet 08
Nord Lead 4
Korg Radias
Virus C
MI Ambika
Novation Nova
Kurzweil K2000
Roland MKS-70
Roland V-Synth GT
Matrix 12
Waldorf Q
Jupiter-80
Yamaha dx7 II
RT Accellerator
I also have an JD800 besides the Microwave II XTK and the Nord, the JD is a fine piece of gear, but it’s one of those synth you’ll love or hate… i love it
Radias is the most oriented layering I use, because one patch is four parts all the time, and you can freely assign midi channel to each part, moreover the midi assignation is stored on the patch !
So imagine :
I created a first patch, I want a bass, a pads sound, and a lead. I will use 3 of the 4 parts, and assign different midi channel on it.
I want to create an other patch for a different song, but now I want to create a huge pad, I will use maybe the 4 parts and assign to all 4 parts the same midi channel : huge and rich possibility of sound.
You can also mix everything, for example : a patch with a bass on 2 parts and a lead on 2 parts also !
This is what I like about this synth, you have free midi assignation stored on patch !
Now, imagine you use the MNM to sequence it and use program change when changing pattern !
Every 6 month, I am saying to my wife, I will sell my Radias to buy other stuff, but each time I reuse it, I say : WTF NO !
Radikal Technologies Accelerator with expansions. Plan to be my next purchase after selling Radias Keyboard and a Virus B Keyboard.
I think from the sound examples I have heard, the Accelerator blows away the DSI P12 as it sounds even more analog that it does with analog filters. Plus the P12 only has “Layer A and B” but if you are only after two layers, you may consider P12. With expansions, the Accelerator is a few $100. less at around $2800. and 32 voices. Has a sequencer as well.
I do lots of layering on the MnM, does that count?
I use the virus ti 2 with the octatrack and the combi works great for me!
The virus has enough power for layering patches in multimode. Also saving the multi’s is easy and you can recall them via the virus auto channel.
did you try any vector synts?
they are rompler-ish, but layering and mixing 4 layers is done quite creatively.
The Oberheim Xpander is great for this! And it has six different voices, perfect with the Monomachine as sequencer.