For the gown and bonnet, I used Lion brand Microspun. It's a little "splitty" to work with, but has a lovely sheen and feels so soft and sweet when it's knit up, and it showed off the ribbing in the skirt just beautifully. For the blanket, I used a Bernat Baby Boucle for a soft, cloud-like texture.
No sooner had I finished the bonnet than I read this great post about preemie bonnets by Tracy at Woolwindings. I'm absolutely going to follow this pattern and the many ways for adapting it. Check it out for some new inspiration on this very special service work.