Superior Threads metallics are excellent, and guaranteed to work. I use them alot, and I free motioned with no problem on my Will-o'-the-Wisp quilt.
http://www.quiltingboard.com/t-27510-1.htm
I always use a topstitch 90/14 as they recommend and have Bottom Line in the bobbin. It is better to sew on a slower speed with metallics too.