I just bought some AKG K340s for about $40. Good deal, yes?
Good deal most certainly, though personally they come in so many variations and they've been modded in so many different ways that I doubt I would like them. I prefer as neutral headphones as possible, possibly something with less colourful and powerful highs.
Logitech products usually come with driver disks for whatever you bought.(if it needed one) Because I know almost all of my Logitech gear came with driver discs.
Err ... depends on what you're getting. The reason the G930 comes with software is because it has its own sound processing, it doesn't use your sound card. You'd be better off getting a decent stereo headset and using your sound card