The intent of this build is to buff up your team fights through your W heal. I feel this kind of build and play style is where a utility Sona provides a niche which would differ from Soraka.

I usually max out E over Q (after W) so your team can move around quicker.

IMO, Zeke's is a nice boost to your ADC when it procs; I like all of the stats it gives ya too (CDR, Armor, and AP). Ardent Censor has some good synergy with Zeke's and can help your team play overall (fighting, taking turrets or objectives). The first four are pretty much the core set. For the last two, the Locket is for team sustainability and Zz'rot for pushing power, each of these add defensive stats as well.

It's probably not perfect and likely some will grumble about it but to each is their own.