I have used machine embroidery threads without issues on a couple of projects. I am just starting to explore thread options for thread painting but will probably use the emb threads. Some of the brands have the variegated thread colors that are recommended.
This seems to be an endeavor where you can't go wrong. It depends on what you want for the final results. I am going to make a large square sandwich to play with threads/techniques first before the final stitch out.
Good luck!