Cheapest twc3 certified oil you can find. Pennzoil syn blend works really good, as does west marine twc3 oil. Ive seen an sxr after 300 hrs on just west marine oil that had been raced for over 2 years at mostly full throttle(had a timing advance and everything), and still could have been ran another season without doing a top end.
Full synthetic 2 stroke oils are a waste imo. Unless you have a special powervalved ski, don't bother with it.