You'll get better results searching for plugins and themes yourself because we don't know exactly what you want the system to do when it's all finished. You say that you want it like the other site, but that's no guarantee that it's going to be exactly like that site.
You also have to realise that just because you want to find pluigns to do everything, there's a very goo dchance that they don't all exist, and if they do there's an even better chance that they won't all play nicely together.
The way that people normally solve problems like this is to see what plugins are currently available that can be used for each part, and if nothing is suitable, you develop your own to suit your requirements. I'd be pretty sure that's what you'll need to do to get to where you want to be.