Both would have pros and cons. Soler would be playing everyday so there's no need for a platoon mate for him. On the flip side, if he's in line for a multi year deal as speculated, then he would clog up DH on a team that likely needs some fluidity there with Vlad and Springer. Joc mashes RHP and there are more RHP than LHP, so he'd have great value there, but then you need to strictly platoon him, which means adding a 2nd player since no one on the Jays currently can fill that role (assuming Schneider is starting at 2B, which he should at this point). If there's a scenario late in a game where Joc is due up and has to be pinch hit for Espinal against a LHP (and you know s*** like that will happen), then it becomes less desirable. If he's platooning with Jansen, then that's a different story, but the Jays in the past have been a bit cautious doing the two catcher lineup too often.
Ultimately, I'd be fine with either one. I'd probably lean towards Soler, acknowledging that he might be the riskier player in general, but the Jays absolutely need power and Soler even at his worst is a .200 ISO guy, so he might be the better fit.