I like the thread from Connecting Threads, lot less lint and fuzz than Coats and Clark.
To answer your question about what to use in your bobbin with the varigated Gutterman thread, use the varigated thread on the top and another color and/or brand of thread in the bobbin but first try it out on some fabric scraps. Sew several long rows of stitching, check the top and bottom stitches and if they are OK go for it. You never know how different threads react to each other. May in Jersey