Configure Server, Joomla, MySQL and PHP to avoid overload

We need to configure a Server, Joomla, MySQL and PHP to avoid overload. More details: - This is a dedicated server hosted on [login to view URL]; - On the server there is a site that receives between 1000 and 1500 unique users a day; - That site causes a huge overload to the server, so after a lot of queries it is down, eats up all the memory and we must restart it in order to go on working. The problem happens when more than 100 users are online at the same time; - The server had been configured as default, as provided by [login to view URL]; - We must configure the way it can support thousands of visitors a day without problems, and hundreds of visitors at the same time; - The site is made in Joomla 1.5.14 and has sh404SEF and SOBI2 installed; How will we work?: you will guide us step by step, by MSN, on how to configure the server. We will follow your instructions and make the proper changes on the server. If is possible that some changes must be done in [login to view URL], [login to view URL], mysql, and even joomla configuration, etc. (Timeout, MaxKeepAliveRequests, KeepAliveTimeout, etc. ) You must be familiar with this terms and made similar projects in the past, if not, plee do not bid. The total budget for this project is $ 50,00.- since are just some instructions and small changes. Have a nice day and happy bidding!!!