Life Leech or Life on Hit for Freezing Pulse-Build

I'm playing a lvl 48 Templar with Freezing Pulse as main skill.
My 4-Link-Combination currently looks like this:
Freezing Pulse - Faster Projectiles - Lesser Multiple Projectiles - Faster Casting

I plan to add Increased Critical Strikes and some way to restore life later on.

Now I'm wondering whether Life Leech or Life on Hit would be better for this purpose.
With Faster Casting as support gem and as stat on my gear I can spam Freezing Pulse rapidly. Combined with LMP this allows me to get quite a lot of hits especially when facing groups of mobs. But the amount of life per hit doesn't scale with my damage and the mana costs are higher than those of Life Leech.

I'm kinda lost right now so I would appreciate any advice/experience on this matter.

life on hit doesn't work on spells.

"

life on hit doesn't work on spells.

This. You have to use leech.

Ah ok, didn't know that. Thanks for the info.