Depends on what you have lift plate wise to do both. I've done it both ways with many different types of hoist. It also depends on how much of the front sheetmetal is on. If it is still stripped a little then stab them both in. THen again, if you are waiting for the trans, gwetting the engine in now will free up some space in the garage and open up a few more tasks which can be completed to get the car that much closer to done when the trans finally does come in.

I say get the engine in and keep going.