In a redraft league, I might go with Upton/Joba, especially if you guess that Joba won't be ready to start until late June/early July. You already have an extremely productive OF, so you don't really need Upton. The real issue, then, is Joba versus Verlander, and Verlander is certainly more established, and has the potential to produce for you before Joba is ready.
Upton and Zimmerman are just sitting on your bench doing nothing for you, so you might as well turn it into something that will add to your team. I have Verlander and I'm hoping he can turn things around. Track records speak for themselves...and Joba has no track record for starting in the big leagues. Lincecum was off and on last year. That's more likely to be the results out of Joba. I'd go for the proven commodity. Plus, if Joba tanks, he will have no trade value. Think of it as a sell high while you can.
The Zimmerman/Joba deal makes the most sense; Zimmerman is sitting on the bench and by the time Joba is starting, Verlander should be back to form. Either way, this is a speculative trade for both sides; you're gambling on Verlander, and he's gambling on Joba. I'd say Verlander is the better bet over the rest of this season.
Upton/Joba for Verlander is pretty fair, I'd say he's getting slightly the better end but since Upton is expendable for you, it's a good deal to make. I wouldn't do Zimmerman/Joba for Verlander, as Verlander is a huge ? mark and Zimmerman's stock will surely rise as time goes on, for he is a late starter. It's worth it to keep him, even if he's on your bench, for a couple more weeks and his stock will rise, allowing you to possibly deal him straight-up for a pitcher like Verlander.