If you cannot get the SKU to show up via the settings then you could use JS to move it around if it appears on the page. You can achieve this if you:
Have JS ability in your Squarespace package
Can redo the titles to read something like "sku#title, e.g. SKUL22456#Vance & Hines Competitions Series...." (you need the # to be some kind of "marker" that tells JS where the SKU ends & the product name begins, so it needs to be something that would never actually appear in a SKU or a product title. Hash is therefore usually a good option)