Where can I find the raw stats data of the current bitcoin network? So that I can build something like this and this in PHP? Is there any official data feed or do I have to go through the entire network programatically to get them?
There's APIs like https://blockexplorer.com/q/ which provide the information, or you can just collect it yourself from your own bitcoind. Most of it is fairly straightforward, but there's a few which you need to do some analysis on if you generate it yourself (like difficulty estimation).