64-bit Centos5 xen kernel and creating a FreeBSD domU

[Deb Heller-Evans]

I'm new to Xen, and have been digging around the Internet.  I have a Xen 
CentOS kernel installed on an Intel 64-bit system:

Linux myhost.com 2.6.18-92.el5xen #1 SMP Tue Jun 10 19:20:18 EDT 2008 
x86_64 x86_64 x86_64 GNU/Linux

Using:
xen-3.0.3-64.el5_2.9,
kernel-xen-2.6.18-92.el5

I need to learn FreeBSD, and so I thought I'd do it under CentOS using 
Xen.  My intent was to load FreeBSD 7.x as a domU, but as I perused the 
Internet, I am seeing that there are issues with Intel 64-bit CentOS 
systems and that the domU kernel needs to have PAE support (I have 16GB 
memory on my system).

Given the current state of the Universe, and the fact that I know next 
to nothing about FreeBSD at the moment, does anyone have any sage advise 
and recommendations for me?

Thanks (in advace - as they say),
deb