I prefer doing a serpentine stitch over seamlines rather than SID. Serpentine is a very forgiving stitch, so you don't have to eyeball it so closely while sewing. It does take more thread, however, so I like to use a lighter weight thread for it -- usually Aurifil 50wt 2-ply, although any 60wt 2-ply would work great too. I used to use a standard thread (50wt 3-ply) for quilting straight lines, and that works fine -- especially if lines are farther apart. However, I found by quilting a doll quilt that regular thread can add a lot of weight and stiffness to a quilt. I personally like the finer weight threads for quilting now.
The "quilting thread" that you mention is actually meant for hand quilting. It is treated with resins that stiffen the thread so it is less likely to tangle and knot. It is not meant for sewing machines, and will gum up the tension mechanism if you try to use it in a machine.