I think you are asking for the actual quilting, not piecing. Yes? No?
It's not just the size, but also the type of needle that needs to be considered.
Whether FMQing or straight line quilting, I mostly use a 14 Embroidery or Topstitch needle.
However, that is with no finality, as I may switch the needle out
according to the batting type, numbers of seams, cotton vs. batik, etc.
The hardest "right" needle to me is when working with batiks.
I've actually been considering using a Jeans needle ... haven't tried it yet. Just thinking!
Getting ready to quilt, I make a sandwich replicating the fabrics, backing and batting used. It might be an extra block or two, or something I put together otherwise, but always replicating what is used in the quilt. Most times this might be a small topper, runner or even a mug rug, so I have something usable once I do the practice work. It gives me the opportunity to get things "right" ... needle, tension, quilting design, thread, etc. before I go to the "real" quilt!