I purchased a couple of starter packs of Arc Poly thread
http://www.sewingmachineoutlet.com/arcstart.htm when I first got my phaff 7570. These are large spools and many of the colors I still have and the thread works great after 10 years from original purchase. Ofcourse the price is higher now than what I originally paid, but the Arc thread is strong, colorfast, and extremely competitive price wise.