Now I tend to prefer to play with 100% virtual instruments.
I think you are on the right track here.
The use of more and more powerful computers, the touch screens and the virtual instruments makes the future. Keep all (or as much as possible) in the software realm will make your product actual, flexible, efficient.
What VI would you recommend to use with vArranger (beside the NI Products)? Could be the new SampleTank 3 a good choice? Did you get the chance to test it with this?
. If you have the latest version of NI komplete, or just Kontakt, then sample tank does not add much, it has the almost the same function as Kontakt, ...
If you want something special and stellar sounding, i can only advise people to go for Komplete Ultimate, which is the perfect startout for any virtuall setup... And the build from there..
Pianteq ..... For perfect piano sound, expandable with just about any major piano sound
Omnsphere .... The best sounding VST with several different synthesis
alchemy, zebra2, blue 2 if you like realtime controllable synthesizers
Or have a look at the arturia synth packs, they have emulations of almost all great analog synths from the past..
And if you want to improve your acoustic sounds, EWQL range of instrument packs is also a great way to go, probably the best acoustic instruments in the world..
And if you like churchorgans, then Hauptwerk is a must
And then there is VST effects, you want to invest in a good set of effects, there is so much going here, and they will hugely improve your sound...
But so far, its komplete ultimate, that gives you allmost everything you will ever need, not the best, but quite a bit better then most hardware synths and arrangers