been researching for a home server - Amahi , Ubunut or CentOS
 

Okay Linux Gurus, I want your recommendation for turning a former xp 64 bit platform home pc , into a linux home server. The current box has good ram and hard drive specs. It will be wiped for a linux home server. Its just we can't decide which distro ? or do we get a copy of VMWare server and install virtual os 's as a home server ?

Have you looked here?

Edit: My vote is for Debian. This link tells you all you need to know to set one up. :)