I have used Aurifloss for some raw edge applique with a running stitch or blanket stitch, but I wouldn't really use it for turned edge applique. It will add bulk and you won't get a nice even edge -- especially if you ever plan to wash it. I like using Aurifil 50 wt (I don't think it comes in a 60wt, but a 50/2 Aurifil is the rough equivalent of a 60/3 in another brand), or YLI silk, but if you're trying to save money, I'd suggest picking one grey colored Gutermann and one cream colored Gutermann either cotton or poly thread. Those two colors will blend well enough with lights & darks that if you're really pinching pennies you can make it work. Ideally, you would match the color of each piece of applique, but if it were my quilt and I had a choice between 5 colors of floss or 2 colors of cotton thread, I'd pick the thread every time.