What minimum hardware requirements should be used for Mac server?

For my senior project I am setting up a web log system for campus use, and we decided to use the Live Journal ( www.livejournal.com ) system since it is all open source and requires only free software. I already have the livejournal setup on a server, and I am working on customizing it… the problem is, the professor who came up with the idea (he will also be the only one maintaining it once I graduate in May) would prefer the system running on a Mac since “that is what he is familiar with”, and so he could do other things while the server is running. Now, the current server running this livejournal system is a server the school used in 1993: 66MHz Pentium, four hundred-something MB RAM (plenty though I don’t remember exact), 2 SCSI drives with 2GB space and two SCSI drives with 4GB of space… pretty bare I know, but its was free… SO, the prof. wants to know what kind of system requirements should he propose to a committee for funding new hardware to run the server. I have never bought and rarely ever used a Mac so I don’t know what to look for… I thought that since the current system is running Fedora, and Macs run a FreeBSD kernel, portability shouldn’t be too much of a problem (no compilation should be necessary since its all Perl and MySQL).

Well, anyone care to propose Mac hardware specs to run a server?