I assume your laptop does not have HDMI, if it does use that to connect to your AVR.
Optical toslink usb seems simplest. You can handle all balancing/tuning and control volume via the AVR.
If you choose an analog usb DAC connected to your amp, you will have multiple connections/wires to deal with, you may have a challenge in balancing the audio (AVRs make this easy), and you will control volume with the laptop. I don't think that would be a desirable setup, but that is up to you and your vision. I doubt you will achieve noticeably better sound this way either.