Thick-Knit Jersey
High-Waist Cross-Back Short-All
And Carol Wright Gifts, along with Dr. Leonards both have terry cloth rompers. however, I've noticed that they (and they appear to be one business entity) have a few complaints about missed orders and wrong items. So use with caution.
And remember to make room for your diapers when you buy them. You don't want them so tight, that the seams split. That'd be embarassing