It's a fallacy to think that the strongest thread is the most desirable thread for quilting. If the thread tears your material apart, it's a lot harder to replace fabric torn on a seam than to replace the seam itself.
For piecing get yerself some 50/3 or 40/2 good quality 100% cotton thread. I use Mettler Silk finish. On my daughters quilt I did use a polyester thread on the bobbin side for quilting, but then again I used a lightweight drape fabric for my back and I think it will hold up (for about a thousand years). For the most part, just use good quality 100% long fiber cotton and you will be fine.
tim in san jose