Sorry sent before I was done...
 
We'd like to create a 'portable' CMS on a laptop running, say, Fedora release 8 (Werewolf).
  
Is this possible ?
 
I'd say it is possible. Take a look at this system here   http://www.redhat.com/promo/summit/2008/downloads/pdf/Friday/Friday_1015am_Bob_Lord_OSS.pdf
 
I've seen the someone from spryus post here before  or your best bet might be contacting them directly to see what info they can share. 

Sean