Basement framing low pipe ceiling
Personally, I would enclose it in a soffit from the pipe to the wall (option 3). That way you may not have to rerun your power cables as long as the window doesn't interfere. Also the drywalling will be simpler.
Edit
You will need to frame out the soffit with 2x4s same as you would do if you framed a wall but it'll be a lot less work and material. Hard to tell from the picture but you may need to move those cables to frame your wall. You'll have to butt the header up against the ceiling joists and they may interfere.
Again, you need to figure out how to frame around that window, especially with the soffit. You need to maintain enough clearance. If the soffit interferes with the window you may have to just wrap the pipes with the soffit.