I use a lot of thread purchased from Ebay. I like rayon, but lots of other prefer polyester. I would buy a small amount of whatever you get - small spools and a limited number of colors, just enough to do the type of designs you have in mind. Then if you don't like the look of the way the thread handles or the way your machine uses the thread you haven't spent a $100 or so in thread - which isn't at all hard to do. I would pick out the design(s) I wanted to do first, then buy the colors I needed to make the designs. In fact that is how I buy my thread even now. When I get a new color it is always because I need it in a design, not because I just think it is a pretty color.