for or until (after 'wait')

Which is correct?

I know that if you use for, it has to be followed by before
I have to wait for him to come before I can leave.

Is it incorrect to say
I have to wait for him to come to leave.

you would have to use wait if you want to use 'to'

I have to wait until he comes to leave.

I don't know which to use in this context.

I couldn't wait for the commercial just so I could get something to eat.
I couldn't wait for the commercial just to get something to eat.

I couldn't wait until the commercial just so I could get something to eat.
I couldn't wait until the commercial just to get something to eat.