Right now, I need another screen for my Dell Inspiron 9300 laptop (it has a 1 inch area of the screen from top to botom that shows nothing whatsoever, it's completely white), and I hope to be able to finally upgrade to a dual-core system (I'm running 3.4 P4 right now).
Why the disdain for redhat?
In addition to Ubuntu(mint is an offshoot of ubuntu IIRC) there’s also live cd offerings from suse.
Many smaller distros offer live cds as well, such as sabayon.(which is tailored towards gamers)
Good luck with your portable.