High CBN strains (according to recent research) might be your best bet, as they have potent antiemetic and sedative properties that can persist for 4-6 hrs. Anything with a tested percentage over 1.0 should have definable effects, 2.0 and above will be noticeably sedative.
FYI, high CBN's are not primarily a breakdown product as has been previously promulgated as fact. My working theory is that they are the primary cannabinoid produced inside the capitate sessile trichome, in response to particular environmental cues...