Video production with multiple audio channels

I want to author some videos that has multiple audio channels. For example, imagine a 4 part harmony being sung. I want to have separate audio streams within it such as:
1. the entire mix (stereo)
2. only the soprano part (mono)
3. only the alto part (mono)
4. only the tenor part (mono)
5. only the bass part (mono)

So that would be 6 audio channels.
I have the audio tracks created already as WAV files. I have Sony Vegas Pro (but only a novice). I have an 8-channel audio interface that would output up to 8 separate audio tracks simultaneously.

My question is:
What is the video file format that would enable the above to be done?
What video authoring software should I use?
I would like to playback on a player that would send the separate audio tracks to the multitrack audio interface (Behringer FCA1616) - but also where I can loop a section (say 5 secs) to repeat. Is there such a player?

I'm on PC. Windows 10.

Thanks