If a quilt shop or fabric store tells you can't use poly thread with cotton fabric just say that is not true and walk out. If another quilter or sewer tells you this tell them they need to update their old wives tales.
I buy pre filled bobbins for piecing from Superior Threads. I'm using Aurifil for the top now because I have a lot of it. I like Connecting Threads Essential Pro on the cone for piecing too. For machine quilting I use Glide Magna Delights no matter what top thread I choose but usually I use Glide for the top too.