In my opinion, the closing shot of the movie should be the scene where Obi Wan drops off Luke on Tatooine. It's a beautiful scene to close with. And with Luke's last name in the OT, I think there's really no point in preserving any mystery about his parentage.
To stretch out the last bit of the movie so it's not so rushed, you can use an altered version of the opening shot from Episode IV:
Just flip the image, reposition the moon a bit, and crop out the Star Destroyer. (The Tantive IV is also upside down, but I don't think that's really noticable.) So now the Tantive IV is dropping off Obi Wan and Luke. Then in the next scene Obi Wan is delivering the baby to the Lars farm.