The curren "top end" weapons are max tier weapons. This means they have a base level of 60. Vendors do not sell items that have a level requirement of 60 (even if they somehow did, it would not be the top tier varient).
Among that, you'll also need 2x tier 14 DPS modifiers, these have a requirement of level 63 which is only prevalent in Act4 and above.
Furthermore, you'll need two of these tier 14 modifiers, which is already rare enough as is from mobs.