I did some testing on how to best sew these sometimes tricky bra-making fabrics. I discovered that the best needle was a Microtex 80/12 with a runner up of Microtex 90/14. You'll need to use 90/14 if you use the Magnifico Thread, and that sews up beautifully, especially on the stretch satin.
I discovered that the very best thread for easy sewing is the Superior Threads So Fine Thread, with the Mettler Metrosene a close second. The Gutermann thread that you can get at stores like Joann Fabric also worked, but the rough surface texture caused the fabric to pull up with every stitch.
The Superior Threads So Fine comes on a 550 yard spool and has the smoothest surface finish. It's a lovely thread, and I've color matched all of our standard colors. The Mettler Metrosene comes on a 165 yard spool and also has a lovely surface finish but is not quite as smooth as the So Fine. I've also color matched this thread to all of our standard colors. I made a bra earlier in the year that incorporated a vining triple stitch for topstitching (it was so pretty!) and it took the better part of a spool of 165 yards to complete.