I don't really like Armory/Venture as a solution. Armory/Adventurer works just as well, as does nearly any nonterminal Treasure-gainer paired with Watchtower, such as Governor/Watchtower or Bandit Camp/Watchtower, and also Bag of Gold/"anything that draws a card".
Gaining and playing a Treasure card is just too easy since the Treasure card doesn't require an Action to play. Any solutions aside from University/Watchtower that can gain and play an Action card?
Well if you don't like Province/Tournament I stand by Procession/Watchtower and Village/Develop.
Take a simple hand of Prssn x3/Wt x2. Play Prssn -> Prssn -> Prssn -> Wt (draw to six, gain a $4 action on deck top, reveal other Wt) -> Wt (draw $4) -> play $4 twice. The $4 card can be Prssn if needed.
Likewise, there are a lot of viable $4 villages you can use with Develop. Take the hand Fortress x3/Develop. Play: Fort -> Dev (Fort to Dev/Duchy, Dev on top) -> Fort (draw Dev) -> Dev (Fort to Dev/Duchy). You could also do this setup with Native Village/Dev.
Another option is Rats/Wt. Hand is Rats x2/Wt x3. Play a Rats (trash a Wt, gain a Rats, reveal a Wt) -> Rats (trash a Wt, draw a Rats, gain a Rats, reveal a Wt) -> Rats (trash a Wt, draw a card, gain a Rats).
Another option would be Upgrade/Wt with either a $6 or a $4 action on the board. Either upgrade Upgrades or Wts respectively and top the inbound card.
Urchin/Wt also works. Urchin x3/Wt: Urchin -> Urchin (trash this, gain a Mercenary, reveal Wt) -> Urchin (draw Mercenary) -> Mercenary
Depending on how you count "gain a card" - Mining Village/Graverobber: Mv (trash it) -> Grvr (gain Mv to deck top) -> Mv (draw Mv) -> Mv. You can either gain back the Mv you trashed this turn or gain one previously seeded into the trash.
A bigger stretch is Prssn/Fort. Prssn -> Fort (trash Fort, "gain" Fort) -> Fort.
In general, you can use any cantrip gainer (e.g. Urchin, Rats, Upgrade, Gov) with Wt and play the gainer multiple times to gain and then draw the new card with an action left. You can use drawing villages with a lot of top decking gainers (e.g. Graverobber, Dev), but you may have restrictions on what you need to make the puzzle work - e.g. Grvr works with most villages if you can start with 6 card hands: Village -> Grvr (trash Grvr) -> Village -> Grvr (gain Grvr) -> Village (draw Grvr) -> Grvr (regained).