As far as the graphs are concerned I was going to suggest the Google Charts Api since the simpler Google Chart Tools look like they are going to be retired in 2015.
They are surprisingly kludge to work with as well, for an application like this I have two requirements;-
* Good support for a timestamp series.
* Dynamic amount of series.
Timestamping is not too bad, you do have to do a bit of working around it bit it does the job but in order to add a series you need to redo the javascript part. Not ideal, with highcharts if you point it at data with multiple series (mining devices in this case) it just displays multiple lines.
If I were you I would contact Highstock and ask about the Hichchart license, it appears to be only $80 for a single web page that is not considered as a "web application".
To get all the features I would want to use I would need the Highstock license and not the Highchart one. And because it displays "customer data" it would be the expensive license.
Neil