I like PurplePotato's card better.
Antechamber seems kinda swingy for swing's sake. Throne Room is swingy, but there's a decent reason that it's swingy, the card kinda doesn't work unless there is a card for it to refer to, and play twice. You could add an "if you don't" clause to Throne Room to fix that, but then that's complexity that isn't worth it.
This card's effect doesn't refer to the targetted card to figure out what it should do, it is just "reveal an Action card, if you do, superlab". It is more like Baron than Throne Room in that way.
By swingy I mean, it's random, to be clear. And it's okay for cards to be random as long as they add something to the game in doing so. Swindler adds this cool question of whether Bureacrat or Coppersmith sucks harder. Throne Room adds this cool effect you can't really have without the collision requirement. Baron adds this question of whether you want to trash your Estates or not.. but I'm not a huge fan of Baron and would say Baron is kinda treading into that zone of "adding lots of randomness for not much in return". But at least with Baron I can Watchtower Estates onto my deck actually buy Estates sometimes and that's cool. This encourages you to buy Action cards for collision. Like Donald X commented about the idea of a Feodum that counted Golds, "Man, I already want lots of Golds", that's not interesting. I already want lots of Action cards.
I like Purple Potato's card more because it's at a price point where missing/hitting collisions isn't as tragic or triumphant, you don't lose games because Duchesses collide you lose the game because Witches collide.
If the philosophy of the card you are trying to do is "A lab that fails dependent on deckbuilding considerations", I would say to make it more interesting by asking you to do something you wouldn't normally be inclined to do. Buying Action cards for your Lab deck is something you'd be inclined to do already. Buying Silver, maybe not. "+1 Card, +1 Action. You may reveal a Copper, if you do, +1 Card, you may reveal a Silver, if you do, +1 Card". Something like that. Or use Duchies and Estates.
If you really want it to count an Action card, make it a special kind of Action card you wouldn't normally buy, like a 2$ Action selected in a bane-ish style or an Action card whose supply pile contains 8 or more copies or whatever criteria that makes things more interesting than "Buy rule: Province > Antechamber >Caravan > Terminal Silver, bot.execute"