Linux / Firefox Optimization

We are a software publisher for a Web Application that is written in Java/Tomcat/MySQL. Our customers HOST our Application (JacoPOS) on their own local server. To use our software, our clients can use ANY web browser. However, we have ONLY been able to use XP clients running IE 6.0 on PIIIs to use our software because we need to RENDER ALL HTML pages within 250ms.. This is because Waiters use our software and CANNOT wait for the page to be drawn. We would like to allow ALL of our clients to USE streamlined Linux desktop with Firefox to avoid XP licensing.. The problem is that the generic installs of Linux (Debian, Fedora, Suse...) with generic xWindows, and latest Firefox are VERY VERY slow as compared to the SAME hardware running XP and IE. Hence we are looking for someone who can develop a repeatable ISO of a VERY small LINUX footprint, with xWindows, networking, and Firefox in order that EACH page can be rendered in the same time that it is rendered on XP/IE So the benchmark is to run XP/IE on a PIII with 256MB of memory, and at the same time run special Linux/Firefox side by side and make sure that the linux installation is able to REDRAW ALL web pages as QUICKLY, if not QUICKER than the XP/IE installation running on same hardware. REQUIREMENTS: 1) You will need two Identical machines; PIII with less than 800mhz, and 256MB of memory. One system will have a FRESH XP install with IE, and the other system will host YOUR Linux/Firefox fonciguration. This will allow you to test. 2) A server running tomcat, mysql, etc.. in order to host our application for benchmark testing. The Deliverable: an ISO that is the GENERIC MINIMAL, FAST, Linux install with FAST xWindows and graphical desktop and firefox.