As a fellow HFB doing T4 I would suggest learning with Harriers as you will be expected to use it in higher level groups as well as in raids, bosses focus on people with high toughness.
Learn to deal with the lower HP pool of Harriers from early on and it will benefit you greatly. I do suggest running Minstrel's accessories (rings, backpack, amulet and trinkets) as it will give you enough HP and toughness. If you go full Harrier you will only have around 11K HP which imo is very low for a Healer who has to stay alive to keep others alive.
This setup should work very well, as you grow confident, replace mace for axe for fury uptime. If you think a group is gonna be bad at dodging stuff then switch to mace for more healing. I would also suggest looking up Rheyo's guide on HFB it is very good.
Before I saw his video I had some trouble keeping groups alive with the "meta" build which barely has any healing outside the tome but now I can actually heal as a healer lol.
TLDR: Run full Harriers with Minstrel's accessories and back. Meta build lacks healing and you should play whatever build you think helps you keep 100% quickness while healing. Switch mace for axe in good groups.
