Do yourself a huge favor and check out SpectacleApp. It's Windows image resizing brought to Mac OSX and it's really neat. 100% free and open source too with sensible defaults unlikes it's competitors.
I can't see how this app (and other layout managers) would help this workflow. I don't move or resize windows. They are all where I want them to be, albeit stacked on top of each other. You click (or keypress) to pick the window you want to use, then use it. No window movement necessary.