This is what I have found. The legs are by far the most difficult part of acquring a complete set of this stuff. The striped Carapaces seem to be the next most difficult part to find.
There is no faction hit involved in the quest, and it is a bit time consuming, however the entire set of armor is 58 AC. Not too bad for 5 pieces of armor. There is also a very low spawn time of the Lightcrawlers, so there is always plenty to hunt, and the fact that the brother (Faber), is only a short zone away, makes the quest well worth it. If you can get exp while doing this all the better.
I hunted near the sanctus zone, and there were plenty of Mobs.
The Ac and the stat bonus make it a very nice and relatively easy quest to do. Depending on the luck of the legs dropping, a couple of good hours in DawnShroud should yield most of the pieces you need.
If you need to combinations just speak to one of the dorfs just south of the SS zone, and follow the string to lightcrawlers, his brother is in Sanctus, in the shop just to the right of the main fountain when you enter the plaza.
Hope this helps )
Cramey
Lords of the Crimson Cubes
Lanys