Poison Arrow / Iron Reflexes Templar - I need your help

http://www.pathofexile.com/passive-skill-tree/AAAAAgUAAnED2wSzBVsNAg6tFE0UdRUgGS4dviSLJ-0pLimlKk0s6TJ-OuE8BTwtPQ89_D8nRZZKfUtJTdhQUFb6WGNZbVz0Xz9fmGebZ6Bn4mqHbPZuqnKpdEF6uHy4fLt82YFvgziHdojxi4yMdozPks2S8548n9-iAKY-plesR6yqrpO3PrndwBnE9sWKxq7G2NSP3Q3igO988B_yL_ZI_MU=

This is what I have so far, I've taken quite a lot of life nodes, and two 'skill duration' nodes that each have 3 points in them and give a total of 45% increased skill duration (to make my poison arrow last longer).

I'll be using poison arrow with an added chaos support gem. That's really all I've thought of so far. The biggest problem with my build is the lack of dexterity, and not being able to use evasion armor/higher level bows. Could you help me fix my build, and make it a little more appropriate? I feel like I would need an Astramentis Amulet just to make this build work. :(

Using 80 points isn't a big deal for me, as I hit 70 in closed beta, and have a different level 57 'mage' Templar on the servers now. :)

You definitely want the silverbranch unique. +2 to skills that deal flat damage is really good, and probably the only way you can directly improve the damage of the skill.

I have heard that increased skill duration buffs both how long the poison clouds last, and how long the poison degen lasts when they are out of the cloud.

Come to think of it, if you use poison arrow, you will need high dexterity to get poison arrow leveled up (around 200 for Max level is my guess). On my phone so I can't check your build, but if you want to use poison arrow, you will need to reach 200 dex.