Re-code PHP secure client area for efficiency and speed

We have a secure client area to our website which is moderately complex and written as one single PHP page, using JQuery tabs to reveal different sections. The website concerns itself with financial information and shows our clients information about their accounts, current balance, historical transactions, etc.

The secure area communicates with a database via a number of different PHP scripts and also uses DataTables (www.datatables.net) and HighCharts (www.highcharts.com) to display this information. Knowledge of these two plugins is advantageous but certainly not required, both are simple to use and well documented.

We have a fully complete and working version of the client area already however this has evolved from prototype code so requires tidying up and making into an easier to maintain version. The current PHP code stands at approximately 1000 lines and there are also a handful of supporting CSS files which will require some cleaning up. Following this initial job, assuming it is completed to our satisfaction, we would look for the successful contractor to help take ownership of the secure client area and handle all future maintenance work and feature requests as separately paid jobs.