OK... I can help as far as getting it to work and have reflections like that in 3Delight... can't help you with anything Iray related as I don't use it (my system is a tad older and not up to snuff for the requirements).

To get the reflective surfaces in DS you'll want to go into the DAZ's Surfaces tab/window with that surface/mat zone selected. Set the specularity "Glossiness" to 100%, then go down to "Reflections" and set that at 100% as well... don't set a reflection map if you want it to use ray-traced reflections. You may also want to tinker with the colour settings for both reflections and diffuse... darker diffuse colours underneath the textures will provide higher and more noticeable reflections as will darker colours under the reflection... but it might take a little tinkering to get the specific effect you're after. Do some test renders until you get things adjusted to your liking...

Once you've got it working save out a DS materials preset and you're basically done...