Heavy Strike - 4 Support Gems?

My build is lightning strike ranger with heavy strike for single target.
I just got a 5 socket chest that's free (already got 6 socket sword for LS)
Curious which support gems to use? Currently I'm using... Faster Attacks, Added fire damage (I have 100% ele dm bonus)
And Added Physical Damage.

I'm thinking faster attacks, physical damage..but what other 2 should I grab? Elemental hit?

Thanks.

Life Leech?

Err anyone?