Who should I pick up? WHIR!

[Brizee8]

I'm currently third overall in my league. Would love some help on what I should do. Here's where I rank in each category:

Runs- third Strikeouts- second
Homeruns- sixth Wins- fifth
RBI- fourth Saves- second
Steals- first ERA- sixth
AVG- eighth WHIP- sixth

Can I improve my team with any of these available players?

Chipper Jones
Brennan Boesch
Alex Rios
Mike Aviles
Darwin Barney
Coco Crisp
Alex Avila
Ryan Theriot
Brett Wallace

And here's my team:

C: Matt Wieters
1B: Ryan Howard
2B: Neil Walker
3B: Ryan Roberts
SS: Jimmy Rollins
MI: Ian Desmond
CI: Adam Dunn
OF: Matt Holliday
OF: Jay Bruce
OF: Nick Markakis
OF: Jason Kubel (recently added)
OF: Rajai Davis
UTIL: Denard Span
BN: Jose Tabata

Pitchers:
Roy Halladay
Jon Lester
Max Scherzer
Ricky Romero
Brandon Morrow
Jorge De La Rosa (recently added)
Alexi Ogando (recently added)
Huston Street
John Axford
Brandon League
Matt Capps (recently added)

I've been using Ogando's spot for a new pitcher every couple days based on matchups, so he's probably the guy I would drop. What do you think? I think my most pressing need is batting average. Do you think my power or pitching numbers can improve with my roster as it is? Am I better off continuing to stream the last roster spot with starting pitchers?

Thanks!