Manulto, I use the same cones of Gutermann 50wt natural cotton thread for all aspects of my quilt construction---piecing, quilting and hand sewing the finishing binding. Maybe I just don't know any better, but it works well for everything for me and my Juki just purrs with the Gutermann cotton thread. Much lower lint than some smaller spools I bought at Connecting Threads.
Your dark grey flannel pajamas sound so cozy!!!