I guess this is too long ago and u made your decision allready but i will post it to keep it for other people in trouble with vaios.
I had some trouble installing linux on a vaio. In my case that was because of the docking station contains the CD-ROM and the whole docking station is connected by firewire. So the cdrom needs firewire to work which is not included in common install (cdrom boot) kernels and it will fail to find its root file system on the CD after booting the bootstrap.
I finally did the job by using the preinstalled windows to copy the first CD to the HDD and install it from there.
It was a PCG-R505V/BD and i am right now typing on it
Chris