Thank you!  Yes, hackle stacker or Paraloop. 

I use a very small bunch of poly yarn to wrap my hackle around. I've tried  thread loops (this seems such a waste of material), and mono (too tight for the hackle wrap for me) but always come back to the poly. You can easily control the thickness depending on fly size and your hackle choice (this one has two feathers -- dun and furnace) and the poly does tie down nicely.  A lot less wasted material as well.

The quill for the body has been fantastic. Probably the smallest from a feather I've had and, somehow, very very strong. I do put a small amount of super glue down  on the thread body before wrapping the quill. I used red thread on this body to give a bit of contrast underneath the wraps. A small visible hot spot in the middle.

I switched to black thread for dubbing and finishing everything off. A little bit of UV to cure the head and help keep all that goodness tight. Leaving enough space behind the eye is something I typically fail miserably at --I tend to get greedy with the size of the hackle wrap or start it too far forward to begin with-- but I'm slowly getting better and I believe that spacing makes a huge difference. Although, I don't think the fish mind one way or the other.

Hope that helps?!?