Schmetz and Organ are fine. I use sharp point or unversial needle 70-90 when using a sew-all weight thread. Piecing should be no trouble.
For freemotion on several layers you can up the size to 100, the sturdiness of a thicker needle can be an advantage. The most important thing is to match neelde size and thread weight to each other, as well as fabric. When using top stitch thread you might have to max out with 110 and 120 in some cases. Densely woven fabrics and several layers often require larger size, especially if you get loops under the fabric and there's really nothing wrong with tension.