Vazquez obviously makes the most sense on a two year deal as you wouldn't have to give up prospects and he would be able to help form a bridge to Quero. However, with the markets rumored to be involved and the trajectory of the FA market this offseason, I don't think it'll happen.
Murphy is the top trade candidate. However, the asking price there is enormous, with the A's reportedly having asked for Nootbar, Donovan, Graceffo, plus from the Cards. For the Brewers, that would be like Frelick, Turang, and Gasser as a starting point, with Ashby perhaps having to be included as well. Again, unlikely.
Which brings us back to Toronto and Danny Jansen. He should be about half the cost of Murphy and would likewise be able to manage the C position until Quero arrives. Jansen also carries with him some upside, considering he's been a backup his whole career and has still put up a 123 OPS+ over the past two seasons with above average batted ball metrics. I'd give Toronto an OF not named Chourio or Frelick, along with Eric Lauer and a lottery ticket. That's a fair trade for both sides imo.
D'Arnaud would also be more than acceptable to me. It's just a question of whether the Braves are going to trade him, or if they want to keep him and play Contreras at DH or in the OF. He should cost around the same or a little less than Jansen, but also has more downside as he's already 33.