Static image server requirements thoughts?

[Tipem]

Hello,

Ok, so I run a website thedailyneopets.com that has gotten 1m+ pageviews within the past month (20,000 visits a day, yikes!). If you go to the website, you can tell that we're pretty image heavy (entertainment-related, yup). Every page on my site AT LEAST has 19 images, I've calculated. And some other pages, as many as 50.

Accordingly to my webstats in my Ensim control panel (which I highly doubt, but still, it's the root server logs), the directory "/uploads/" accounts for 40% of all of my total request last week (2406974 to be exact). The uploads directory is where all of my staff members upload their static images for pages and guides and such (basically where all images are stored). I also have an /images/ directory which serves images for JUST our layout (e.g., headers, footers, sidebars, etc) which accounts for another 29% percent of all incoming requests last week week (another 1736824 to be exact).

Now the server I'm on (CentOS, 6gb of RAM or something crazy like that, I can't remember exactly but minimum is 6gb) is actually handling the load quite well. It doesn't crash or anything. I'm nice and happy. But because we're handling an exceptionally LARGE load and considering most of the load is just static content, I figure now would be a good time to start splitting up servers and "branching" out instead of getting to the point where my current server starts crashing.

Based on my stats, what kind of server requirements would be needed for a STATIC IMAGE SERVER? Notice STATIC which means it wouldn't serve dynamic content such as php/mysql scripts. I was thinking Lighttpd + minimal installation of CentOS (Lighttpd is super fast for static content, I love it). But what kind of hardware would I need to handle nearly 69% of all my total requests? I currently have a free server sitting around that has 3.7 gb of RAM with a Pentium 4 in it... could this work?? Again, it wouldn't need to run big apache modules... just lighttpd and static content. No need for a bulky control panel such as Ensim either; just a dedicated IP box.

Let me know what your thoughts are. b)

Tipem

P.S. I'm new here.