I managed to install Ubuntu 12.10 along with Win8, and also found a solution to the wireless problem.
Based on posts from this forum, here's what I did:
1. I prepared a USB-stick with 64bit Ubuntu 12.10 and Boot-Repair.
2. From Windows, I created a partition, by shrinking the primary windows partition.
3. Booted from USB, and chose - Try Ubuntu.
4. Opened a terminal and disabled the RAID as described above.
5. Started the intstaller, and chose: "something else" as installation type.
6. Created the root and swap partitions, on the empty space created on step #2.
At this point, I had Ubuntu working, but no GRUB. That is - when booting the machine, it would start Windows, unless I hit ESC and chose to boot from Ubuntu.
1. I started Ubuntu, and ran Boot-Repair, and did a "recommended repair".
2. When I was done, and rebooted, I got the GRUB (I think that's how it's called..) menu, with lots of options. However, none of the Windows options worked.
3. This was fixed by going to the EUFI settings and disabling "secure boot". I am not an expert on this, and I am not sure what the implications are, but it seems to have worked, and now both Ubuntu and Windows work.
Fixing the wireless: (I found this here)
sudo apt-get install linux-backports-modules-cw-3.6-quantal-generic
Thanks a lot for all the help!
This was a bit of a challenge