Lightning Crit Scion Build

Just looking for some advice on my build. I'm going for a Lightning based Scion mage with a high crit rate.

http://www.pathofexile.com/passive-skill-tree/AAAAAgAACGcPxBGWEdsTnhUgFVAWbxg8GNsZhhzcHpQhwyepKPoppSpNLOktRy2oM3Y6szt8RZ1GcUp9TipQQlXGV-FapluvXfJmT2egZ71vnnBScNV08XqqfjN-WX_GgUmCHoLHgwmFMod2iEKMNo9GkAqQ1pI4ks2S85Mnkzqa4JuhnaOio6SRpwisP6xHsZCyOLQMt9a4k7jKvSfAUcHFykrPZdDQ2E3a3dsL21ncV9zH3Q3rLOvu7m_yHfPq9On5Zfno_Kv8xQ==

I stopped playing my summoner(lvl 45) and re-rolled a Scion mage for some more dmg output. Just in standard league. I'm going for a high crit rate and multiplier.

I've went into the shadow area to grab so crit nodes and went up for eldritch battery for higher mana rate.for offense. On the defensive side I went down and grabbed Iron reflexes and Mind Over Matter. I've left several points blank as I'm not sure if I will need more life/resistances/mana or crit.

So far I'm lvl 30 and I went up to get Eldritch battery first. Just looking for some feedback where I might need to go next.

Also any good skill combo's for fellow lightning mages would be appreciated.