If you want to try a long flowering sativa landrace strain, Ace does have some good options. Their Honduras is as close to pure landrace as Ace gets, it's a great plant, and I've heard good things about New Caledonia. If the flowering time is too reasonable, it's probably not a pure sativa, the temptation to hybridize these plants is too strong for a lot of breeders. Snow High is another good source of pure sativa classic strains like Colombian Gold, Vietnam Black, and Panama Red as well as a lot of good stuff from Mexico. Swami has a good collection of old sativas too. I like the himalayan charas sativas too, you can find those at Ace or at the Real Seed Company. They're bred for resin production for making hash, but the high is very different with them, very warm and happy-some of these are Malana Cream or Nanda Devi. These plants all result in buds that look very different from modern dispensary buds-to be honest they end up looking like janky ditchweed, but don't let that throw you off, they are most definitely worth growing and the range of highs you'll find is unlike anything that can be bought in a dispensary. Tropical seeds is a good source for African sativas too, their Ciskei is a great option for a South African sativa.