Henni,

Surely its deviating from your current situation but I still feel the best bet would be a light MIDI controller with an Audya 4 Module instead of the Audya keyboard assuming it has all the functionalities of the keyboard version. And you could save on the module over the keyboard and use it to buy a Roland BK-7m and / or Yamaha XS rack[all played through the vArranger since it supports other style formats and has multiple MIDI Outs for each channel]

I do use Oxygen MIDI controller + 4X4 MIDI Interface + vArranger running on my desktop + SD-2 and PSR S-950. But I play only at home so there is no hassle of carrying two keyboards and the related setup etc. But yes an all in one TOTL like the T5 or an Audya gives you a easier learning curve and a faster setup.

Regards,
Jez