Yet another Single Sink to Double Sink Vanity

Hi Everyone,

Just wanted to ask for some advice before I start tinkering with my second floor bathroom...

This is the current setup:


The pipe on the lower left is the (4"?) stack, the pipe in the middle is the (1.5") vent, and the pipe on the right is the (1.5")drain for the existing vanity. Unfortunately, changing anything between the stack and the wall will be exceptionally difficult due to the way it was installed - There is a floor joist directly underneath the wall so the pipes actually come up through the subfloor about 6 inches away from the wall and then enter the wall cavity...

Would it be possible to do this?



Would this be better?



Are there any other possibilities?

Thanks in advance!

You can't run waste down a vent.

This drawing would be the best, as it keeps the vent a vent.