Surround Sound speaker question...

[z24lucifer]

I currently have a 5.1 setup, but am thinking of swapping out my two rear speakers for something that produces "better" surround sound (by better i mean directing the sound in a better fashion for my current system).

Right now, I have Infinity Primus 150s as my rears. These speakers are not angled ideally, given the way my room is setup (please see pictures attached). I find that I don't get as much rear sound as I might be able to get. So, I thought I'd ask for some opinions here...

So, my question is, if I changed the rears to something like one of the following, would i get significantly "better" surround sound from my rears?
(ideally i would like to keep the rears on the same side of the wall to hide holes I left )

- Klipsch RS42 - http://www.klipsch.com/products/details/rs-42.aspx
- Klipsch RS10 - http://www.klipsch.com/products/details/rs-10.aspx
- Polk Audio FXIA4 - http://www.polkaudio.com/homeaudio/products/fxia4/

Pics of my current rears setup:
DSC00844.JPG

DSC00848.JPG