I'm surprised people are telling you to keep a closer here. 5 keepers is very shallow so I'm sure that there are very few owners keeping closers, hence there will be a large pool to redraft from. Not to mention the volatility at closer is the highest than any other position in fantasy baseball. Wilson is not an option, IMO.
Honestly, I would keep both Haren and Aramis and throw back Bautista. I know he probably carried your team last season, but the fact is he will not repeat what he just did. It can be debated whether or not his power is legit, but IMO, it cannot be debated that he will hit 50+ homers again, he simply won't do it. I like Aram better than Bautista but that is just my opinion.
If Bautista is already locked in, then my vote goes for Haren.