use whichever size needle is comfortable for you and you can achieve the stitch you want. I prefer the needles made in England over the Japanese needles (I believe Piecemakers are Japanese needles). I have always found those are thinner and bend more easily. I like John James or Hennings needles. Some even come with larger eyes.
As to thread. Again what works for you. I have quilted with regular sewing thread to get the color I want. I always use bees wax or Thread Heaven even tho the thread is made for hand quilting. Recently I couldn't find my Thread Heaven and used Tacky Finger or Sortwink (I believe that is the name and isthe stuff used on fingers to sort paper) It worked great and even on cheaper thread lessened the tangling.
I my hand quilting classes we use the Hand Quilting thread made by A&E. It comes in limited colors but is about .99 at JoAnn's. A survey taken a few years ago rated this one of the best. I also use the Tacky Finger when I machine quilt as I don't like using gloves and it gives some tacky to my fingers for free motion.