Duvet:

I have this Duvet Set/Pillow covers in two colors. I have received quite a few compliments on how great they feel from overnight guests. Still holding up after about 2 years of use.

https://www.amazon.com/gp/product/B01BCP73L0/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Sheets:

I have one set of these and I'm a huge fan of them. They get softer after a few uses, but feel extremely solid. Thick. But they don't really make me sweat even during the summer. Like stated in the reviews, they do shrink quite a bit during the first washing.

https://www.amazon.com/gp/product/B01NCXHF0S/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Used this set in the past. They are ok but for the small price difference I would go with the other set. https://www.amazon.com/gp/product/B00Q7OE3VA/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Comforter:

As for something to put inside the cover, I've been pretty happy with this guy.

https://www.amazon.com/gp/product/B005TOVZSS/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1