Summon
I like that. Donald X. talked about a similar card, which was basically this, except it offered +$2 instead of +1 Action and allowed you to name any card type. It got scrapped, because it was strictly superior to Chancellor (because you could always just name a type of card you didn't have) and too weak to cost at $4.
Restricting it to only actions or treasures does the trick, though, and the +1 Action instead of +$2 seems like a better idea. But that probably makes it a weaker card. If you name an action, and that's the next card to show up in your deck, then you've done no better than if you'd never bought the card in the first place. And while, if you skip green cards to get to it, that's a good thing, this is probably counterbalanced by the treasures you're also liable to skip. So I think the benefit of the card lies entirely on being able to look at the rest of your hand and deciding which type would help you out most.
That's not insignificant and very possibly worthwhile as a $3 buy. I'd guess that's probably where it needs to be, but you might playtest it $2, too.
Wooden Bridge
I worry that this is too powerful. The self-trashing maybe makes it okay, but since it's a non-terminal, it would be perfectly possible to rush the stack and wait until you could play them all at once, in succession, to activate them. Play 7 in a row, and you can now buy 7 Provinces. Because they self-trash, you can only do this once, but, then again, you only need to do it once. Of course you can do this with Bridge too, but the fact that Bridge is a terminal makes it more difficult to play them all together. You need a more specific kind of outside help.
But I'm not so sure this is brokenly powerful. For one thing, you don't get any real help from them as you're building up to that mega-turn. (When not activated, they're essentially Coppers with +Buy.) And you still do need outside help to get them all together, though that help can be any of lots of things, including Chapel, Hunting Party, Labs, Native Village, Golem, and Warehouse. But if that help is present, and this is the dominant strategy on the board, so be it. I think it will be a card that requires more playtesting than the usual, but, again, I don't immediately see any reason this can't work. Certainly I think it's different enough from Bridge to warrant the attention.