That's a pretty vague question. The most important information, like what you intend to use the server for, is left out. For example, I have a Gentoo Linux PC with an AMD 1400XP processor and 512Mb RAM and a 200 GB HD running
Tomcat on a DSL line with a static IP running my private web site. All it does is display pictures of my kid, so it doesn't need much horsepower or throughput. I also use it as my main home PC, so it is running X/KDE and it has all the trimmings like OpenOffice and Mplayer and so on.
Now, for the public web site I maintain for my employer we use dual-processor SPARC systems in a failover arrangement. Both boxes run Solaris 9 on dual processors, 4GB of RAM and 5 4GB disk partitions hosted on a seperate disk array. We use Weblogic 6.1 in our production environment and are in the process of moving to 8.1.
So what are you trying to accomplish with your server?