>>311877330
Reverb G2 should be out in November although I'm not sure they've given an actual date yet. It's an Index headset with better lenses and displays, but inside out tracking [spoiler]that admittedly looks fine for most cases[/spoiler] and worse controllers.
I don't think it's safe to get your hopes up about Decagear until we see something significantly more concrete. It's 7 months away at best, and the hardware is nowhere near final. I hope they actually manage to deliver though.
Quest 2 does have built in audio for what its worth, but it's not as good as the speaker setups on the Index and G2.