HiFiMAN RE0 seems to be unavailable. Is their a newer model or replacement and is it similar?

Not really going to use mic since I don't like talking much and on PC it's all text anyways. So if I want the best possible sound I should go for the AD700x right? Also will I need a soundcard for my PC if I get these?

Great guide Mad Lust. On Amazon the ad700x is considerably cheaper then the ad700 and I'm not sure which to buy. Anyone here try both of them and know what the difference in sound is. I don't have that much money since I'm in highschool so saving is important to me.