Hand quilting thread is coated with a wax- like substance that helps with pulling it through the fabric and also assists with durability. It should not be used in the machine as it will gum up the tension discs. Mettler hand quilting thread is the only one that I know that you can also use in the machine.
There are many good brands for quilting cotton: Gutterman, Mettler, Aurifil, Superior, Wonderfil, Madiera, are just some of the brands I have used and they are all OK.
Try the Superior Thread company:
http://www.superiorthreads.com/shop/