The i100 weapons cost 10 Rowena's Tokens (Soldiery) and an unidentified Allagan tomestone. The i120 weapons cost 10 Rowena's Tokens (Poetics) and an encrypted tomestone. If you're missing the tomestone items or don't have enough of the Rowena's Tokens, all four can be purchased from Auriana, who's right next to Aelina.