Iron Reflexes and Leather & Steel, how does this work.

When you take Iron Reflexes, your evasion becomes armour. I'm trying to figure out whether i should take armour+evasion bonusses (2x8%) or simply evasion or armour bonusses (10%).

What happens first: the Iron Reflexes skill or the % increase in armour and evasion? And what happens with my evasion if IR comes first?

Say i have 200 armour and 1000 evasion.

a. So is it true that taking the 8% armour + evasion passives now gives 8% of 1200 armour and 8% of 1000 evasion: 96 extra armour and 80 extra evasion = 176 armour

b. Or will it give an 8% bonus to 200 armour and to 1000 evasion: 16 armour and 80 evasion = 96 armour

c. Or maybe it gives 8% to 1200 armour and to 0 evasion: 96 armour

If a. is true i should take armour+evasion bonusses with evasion gear.
If b. is true i should take evasion bonusses with evasion gear.
If c. is true i should take armour bonusses with evasion gear.

it works only once. you dont have any evasion when you take iron reflexes so how could it give you any bonus to evasion ?

I'm afraid i dont understand what you mean. If you're talking about situation a., it probably doesn't work this way. But because you have IR doesn't mean there is no Evasion number being calculated in the background. Like an invisible Evasion number that always gives you 5% evasion. Even if evasion is 0, the order in which this (and many other stats) is calculated is of importance.

Take a look here it may help,

Thanks that helps, i should choose the 10% bonusses because L&S doesn't double stack, but still i am not sure whether to take armour or evasion.

Apparently the percentage increase is calculated after the conversion of evasion to armor. This would mean that if you have any base armour from items it is better to choose armour bonusses, since this bonus is calculated after evasion is added to the armour.
(10% of 1200 as opposed to 10% of 1000, in my example)

But in another thread i read that you should aim for high evasion armors, since it will get multiplied with your agility. Full evasion gear gives you 20% more armour than full armour gear. So, if my aim is to wear full evasion gear, then it doesn't matter whether i take evasion or armour bonusses. But just to be sure i get the max bonusses, even when i do wear armour gear, i should go for 10% armour increase bonusses. Right?