grannyj~ I have a machine similar to yours, and I use a same thread in both top and bottom. Sometimes different colors. I wind my own bobbins too. For threads, I have used Mettler, Signature, Conn. Threads cottons, Aurifil. Had good success with all. Have found that the machine doesn't like Presencia. The various threads from Superior offer you lots of weights and cotton, poly, etc.
Hope you find a few threads that work well for you!
