proliant4500...I want to upgrade...?

[CA1282224]

Hi guys...hopefully someone will be able to help me out here....I have a free proliant4500 given to me that I want to upgrade.
I was told that it can be upgraded to a better processor...what is possible exactly with this setup...can I upgrade the board?
can i upgrade to have actual harddrives instead of scsi if i change the I/O board.
I am a newbie and want to know as much as possible for what can be modified on this chasis, body for reusing this server.

so far i have it with a pentium I 166.
1 cpu only and maybe 300mb. ram.

I know i can greatly change this, but want to know what are the limits...alos being money concious.