Here is a stabilizer guide:
http://www.emblibrary.com/EL/ELProje...px?page=PR1153 It tells you what type of stabilizer to use with different fabrics. Mostly I use a water soluble stabilizer - various brands like OESD or Sulky. For threads I have collected Sulky and Madeira threads - definitely use poly for it's strength and how well it washes and maintains color.