You can farm primalist tokens from the rotating elemental storm mobs on the Dragon Isles and the forbidden reach and convert them in the catalyst for normal VoTI set. To get the heroic variant you upgrade each piece at the upgrade vendor with the untapped forbidden knowledge currency. Both are still RNG to receive the gear slots and currency drops you need and will be time consuming, but is not limited to a weekly lockout or poor drop rate from non-legacy loot like farming the raid.
Slightly more deterministic, you can purchase individual pieces with the overflow currency from Mythressa, a vendor on Forbidden Reach, but to upgrade it to the second tier (primalist tokens are automatically tier 2) you will need another currency, storm sigils. Typically, any catalyst and upgrade vendor will work for legacy gear, not just the ones in that expansion zone. You can mix and match using both options for items you are not lucky to get early on. The amount of currency needed for upgrade varies by individual piece.
So two options are:
Buy level 1 items from Mythressa with elemental overflow + use storm sigils to upgrade items to rank 2 (then convert in catalyst for normal appearance) + use untapped forbidden knowledge to upgrade to rank 3 (heroic appearance)
Learn rank 2 items from primalist tokens (convert in catalyst for normal appearance) + use untapped forbidden knowledge to upgrade to rank 3 (heroic appearance)
Here are some links for each you can investigate further: