Mage build for Heroic Farming after fresh 80?

Hi all,
Recently have a fresh 80 on Lord server. Didn't have loads of gold, been farming a bit to get a couple boe's but not too much so far. Have 2 set of t9 now and some heroic dungeon gear.

I've been playing the following 2 builds:
Frost:
https://wotlkdb.com/?talent#of0Vzu0c...0fzgfkt:Rin0mc

Fire:
https://wotlkdb.com/?talent#of0Vcu0c...hVubhct:VLi0mc

I won't be raiding anything other than weekly for some time, so I don't really need a huge single target build.
I will literally be spamming heroic dungeons and ICC rep farms for a while.

I would love some advice on what's the best approach / spec here as I really don't enjoy being carried.

My current GS is 4.4k and my crit is sitting at around 36% self buffed.

Thanks so much!

Link to talent builder if you feel like making builds to help me out :) : https://wotlkdb.com/?talent#o