Shifting/Moving basement Ductwork

I'm hoping to finally get started on my basement project, and am really hoping to be able to move/shift 2 pieces of ductwork essentially 1 ceiling rafter over but still be able to keep the vents where there are leading up. If you look at the below, I was hoping to be able to move those two "U turns" further back into the basement, and then connect to the vent in the ceiling/floor with some sort of 'flat' vent? I'm probably not using the right terminology here. But I attached the below pic to give an idea. These 2 soffits are sorta of in the middle of room, and would be a major eye sore in having to box them right in the middle. Edit. I can't seem to get an image to attach or post. But I uploaded what I'm referring to on tiypic here: