Hey Brian, Yes, you really should hire a post production mixer to take care of this for you. In that scenario, the mixer will deliver 5.1 tracks of audio which will have to be mapped properly on your timeline for export. If this is not an option for the budget, You’ll have to mix down your tracks so they can be mapped to 5.1. Typically dialog is mapped to front left and front right, maybe in the center also depending on the scene and desired effect. FX and Music are generally distributed amongst all speakers, with the rear left and rear right being used for music and sounds that you want coming from behind the audience, such as approaching helicopters, gun fire or whatever– and this is why you need to be able to monitor in 5.1. Also, consider that if there isn’t a budget for this, the practical thing is just to export in Stereo. I did that once on a film I shot and edited and it worked out fine for festivals and streaming.