The light version of the Heavy Healer. We're still running Rattlecage for the Major Sorcery buff, but instead of having it on the armor we are opting for putting it on the weapons and jewelry. Now we can benefit more from the light armor and having higher natural Magicka recovery than before, unfortunately this means we won't have as much HP or defenses and we won't benefit from the extra resource recovery by heavy attacks. Though now we can now also invest into a new mundus stone since we needed to get the extra Magicka from somewhere on the Heavy Healer.
For a monster set you can use something like Nazaray, Symphony of Blades, or two 4% Healing Monster pieces. If you go the mythic route you can use Spaulder of Ruin if sustain is possible.
For Subclassing you can now provide yourself and the group with Major Sorcery/Brutality, as well as Minor Brutality and Toughness. We also can provide Major Prophecy/Savagery to ourselves through Lotus Flower, however if necessary use this as a flex spot for Purge or Blood Alter. We no longer provide the group with Minor Sorcery but Minor Brutality makes up for that. We do lose a lot of Weapon/Spell damage due to passives and the fact we no longer will be running Rattlecage as we don't need it for Major Sorcery/Brutality as we will be providing it for the ourselves and the group now. Of course it was always possible to drop Rattle for Spell Power Potions but now we no longer will need either. We're running 2 medium armor to make up for some of that lost Weapon and Spell damage, and of course Spell Power Cure will make up for a lot of the lost Weapon/Spell power lost from our Heavy Healer counterpart. As for our second set we can use Stone-Talker for group sustain, Powerful Assault to make up much more of the lost Power while also providing it to the group. Likely you will run one of the two. Master Architect is also a possible option though another an ULT gen build would make much better use of this.
A Medium armor healer is possible by using Powerful Assault as the body, Magicka sustain will drop and critical chance will go with it but you'll be more survivable (still less than Heavy Healer) and have tons of Power for raw heals. If you do crit heal though they will be stronger. Consider looking at Version 2 setup for a Medium Healer.