Raw bitrate for stereo 384 kHz / 24 bit is ~20 Mbps so even the cheapest plan would be fine for streaming audio. $60 for gig speed is a good deal - especially if you'll have multiple people streaming content / downloading games.
Most likely the technician will install a optical network terminal (ONT) which will convert the optical signal to wired Ethernet. You don't need to worry about isolation since Ethernet is transformer coupled. Power surges could be a problem, but I've never had a network interface die on me through various blackouts / brownouts. If you're truly paranoid, it might be better to use wi-fi.