Drop product shots and connect the attribute sheet. Tallyrack reads the SKU straight off each filename and joins it to the sheet row carrying the same SKU — the price and every other attribute come from the sheet, so they stay right when they change.
Everything before the third dash is the SKU; the number after it is the photograph. Number them only when a product has more than one — -1 is the cover. The number decides the running order, not the order you drop the files in.