i quilt with just about anything..from clear to Masterpiece,Aurifil,Gutterman,bottomline,verigated , and everything inbetween!
i buy threads from the LQS,Joanns or
superior threads,
http://www.superiorthreads.com/
check out superior threads videos!
redrock is another place.
http://www.redrockthreads.com/
i piece with a cotton, quilt with what i want. hehe