I'm planning on creating a Media Center using Ubuntu as the Operating System. Would someone please tell me if the following is possible

I plan on having 4 hard disks set up in a RAID5 configuration for storage.
rTorrent with ruTorrent for torrenting from this box.
Boxee for Media Playback.
Act as a Basic File Server.

One thing that I really need is to be able to create the RAID5 set up one drive at a time. (Start with one drive, then add another one later, and then add a third. and then a fourth).

If it would also be possible to run a LAMP stack and BIND that would be great!

If you could point me to tutorials on how I can set up the file server and how to set up the RAID, I'd really appreciate it.