What one of these two would make the better Sci-Fi story?

A story where humans are “immortal” so to speak, as i mentioned here: http://www.fluther.com/102407/is-my-idea-for-a-sci-fi-book-any-good-and-how/

Or…

A story set 33 billion years in to the future, where humans are now facing the inevitable end of the universe.

While the technology talked of in the story will need to be mind blowing, it will take a little bit of a back seat to phylosophical ideas. In the entire 33 billion year history or humans, we never found any intelligent alien life. Sure, we found some microbes, and even some life that resembles that of reptiles, birds, mammals and a few other kinds of life. But never anything that shares our intelligence.

In all 33 billion years, we mapped our entire galaxy, along with a few others. We even moved planet earth atom by atom, to a totally new galaxy, to avoid destruction when the milky way collided with the andromeda galaxy. and yet, we never found intelligent life, and now, it looks like we too are about to end.

The immortality story will be a moral dilemma on greed and other human traits. The story about the end of the universe will be heavy of phylosophy, and even maybe some theological pondering.

What one would make a better story?

B.Q. Do you think my kind of ideas for Sci-Fi stories would be better as novels or short stories? .. or, maybe even a comic?