Some suggestions for the best thread for machine piecing. My LQS have stopped selling Gutterman, this is what I have used the most.
Have you considered buying your thread online? I just Googled "Gutterman Thread" and came up with lots of hits.
Southwest of San Antonio
I use Aurifil almost exclusively anymore.
I have had really good results with the Essential cotton thread from Connecting Thread. It is a really good value.
If you want to buy American try Superior Threads for really good quality. Sign up their monthly newsletter, they have great sales and Try Me specials