Add cache to a php/javascript game servers query

I currently use a PHP script that outputs json and then use javascript to output it on web pages. The json: [login to view URL] The PHP source: [login to view URL] The javascript: [login to view URL] The problem is that sometimes some servers takes too long to answer and there are sometimes a lot of queries being sent with the increasing traffic on the website. I would like the PHP script to query the servers every 3 minutes and to cache the result for that time. So that everytime the [login to view URL] page is called, it doesn't requery the servers again as it is right now. I would also like some tweaks done to the javascript I currently use to support timed out connections and offline servers. At the moment, if a server is unreachable, the script either breaks or take forever to query. I would also be willing to pay extra for a rewrite of the code to make it more flexible and easy to add/remove new servers. If you are willing to make this "full rewrite", please mention it and include the price in your quote.