Just my two cents, but I would not combine a cotton yarn with the chenille - I don't see what you would gain by doing that. I typically only double knit if I am trying to create a color combo or knit a blanket or scarf a little bulkier. I don't combine fibers though - if I double knit it is either all cotton, all wool or all acrylic.
The chenille is a bulky yarn and IMHO makes comfy coverlets, scarf, hats etc. There are many people who don't like Lion Brand and other acrylic yarns, but they are great for learning to knit.