I understand the basic requirement but this is totally dependent on layout. This is due to the fact that the show hide icon needs to be always present. Therefore, this will effect layout.
Likewise, Hiding or showing elements can be tricky if you dont have the exact layout down. This is due to "inline" style. It "removes" the content from display consideration which means that the HTML for the page changes temperarily until you stick it back in there. This is not the case with hiding "block" but then you have big gapping spaces where the HTML is but just not visible.
You mention that you want it to be like the vbulletin show/hide. What does this mean? Where is this feature?
For example are you going to have rows that are hidden or shown wihtin a given table?
Give me an example of the layout (HTML) that you require AND where the content will reside within that layout and we will see what can be done.