Nylon pajama shorts are available for men and women, but you'll have to do quite a bit of searching to find a pair that is labeled as nylon and sold as sleepwear, especially if you're looking for a shorts and shirt set.
Roaman's: Although predominantly a plus size clothing retailer, the Roaman's mail order catalog does have a good selection of plus size lingerie including bras in various styles, panties, sleepwear, hosiery and shapewear.
Once upon a time, plus size sleepwear options consisted of shapeless gowns that resembled muumuus, and a handful of tops and bottoms that would just about hide a woman's body beneath yards of unnecessary fabric.
All of these sets feature camisole tops paired with cute little shorts that will be comfortable as sleepwear, but also make for pretty morning attire while you sip your favorite hot beverage and read the paper.
Quality sleepwear is available from a wide variety of retailers, from mass merchandisers like Wal-mart and department stores like JC Penney, to Internet retailers specializing in children's wear or slippers.