Ideally, you'll probably want some of both, and possibly some enchants that reduce spell cost as well.

Basically, they will allow you to do different things, so lean towards which you want to do based on your setup.

1) Spell Damage and Max Magika increase the strength of your heals. Great for burst heals as a Templar, but will also affect HoTs.

2) Magika Regen and Reduced Spell Cost help with sustainability. Basically, how long you can keep heals up. Great for longer fights like boss fights, but less useful if you're not using a ton of magika in the first place.


Basically, having stronger heals means that you need to use those skills less often, which reduces the need for regen and cost reduction. This is why most people focus on that, and just get regen along the way if set bonuses grant it.