Looking for a specific plugin

Hi,
I have a WP blog that has Frontier theme.
Now, the posts are sometimes quite long and it makes the frame
around the post long, and creates gray and dead areas that has no
content on the sides, which I find boring and not very aesthetic.

What I was thinking, is to use some plugin that devides the posts
for example to 3 parts and each part is in different page.
This way I keep it nice and clean.

Here is a post from my site so you could see what i’m talking about:
http://stronger.co.il/%D7%95%D7%99%D7%98%D7%9E%D7%99%D7%9F-d/