When I couldn't decide on the exact way that was best to end anything, I just wrote one, saw how well it fit, and then wrote out the alternatives. I find the problem with ideas is that you don't always get a clear idea of any of them until you can see it more concretely, and for me, writing it helps. Once you have something down, it might be easier to find what sorts of thing the ending needs, or doesn't need. Then either you fix up what you have, or you write a new one.
Worked for me, well enough. Since you say you have ideas and you're not sure which one's best, I'd say start with an idea you think might work and just see what happens. If nothing else, you'll get more done than spending time staring at the screen yelling "what now, guys?"
My two cents.