I would say any machine with good tension balance and true timing. Straight stitch and if desired a basic zizzag are all you really need for piecing. I would by preference choose a sharp needle (I personally use the Schmetz quilting or metafil needles) at the start of each project. A method to find your 1/4" from the needle seam allowance is also helpful. On the up side, I have just purchased a Bernina 1300MDC serger that I am contemplating using for basic piecing. So anything that you are comfortable with and will use works. Oh, yes, don't forget to clean the bobbin race area and the feed dogs --- our passion for piecing can create a lot of dust bunny lint in those areas.