Implementing comparison feature

I’d like to get some advice on how to create a comparison feature like the one at GSMarena.com, direct link to an example page, where two cellphones are being compared.

http://www.gsmarena.com/compare.php3?idPhone2=2000&idPhone1=2005

I’m really unsure as to how I should approach this problem. Should I try using Iframes or create some sort of PHP or other script or try to design a plugin. Thanks in advance.