You say you are going to use many machines to piece? Just remember each machine may give you just a little different stitch......as far as a good all machine type thread.....a poly covered cotton of 40wt would probably suffice. You also say "QUILTING".........on all different machines too??? Again, there could be a tension problem with some.......again I would use a poly covered cotton thread......JMHO And my final question: Why use all those machines on one quilt??????? I cannot picture that process in my mind's eye......