I got my new 320GB HD installed and recognized and will be setting it up for PCLINUX in a few days. This will be my primary computer as I have had my wife running her computer on PCL for a couple of years now. I've never had some much space to waste

so I have been reading about how others have set up the partitions in their HD's and here is my current game plan.
I want to run PCL as my OS in the "/" partition and think I would like another partition that would be available to use for testing of other versions of PCL in the future or newer beta releases, etc. I intend to load and use VirtualBox (VB) in order to run WinXP as needed. I'll probably just disconnect my old existing 30GB HD as it is showing signs of failing according to SMART and I might turn it on once a month for backup. I don't see any reason to leave it running all the time if I am not going to be using it.
I have read about the different views on having a separate partition for "/home" and that is the direction I plan to go since I was told "/home" will also be used by the virtual machines that I may run in VB. However I also like the idea of having a separate "/data" partition but I'm not clear on how I redirect PLC to store my documents, files, music, etc. to "/data" instead of it all going into "/home"?
Here is what I'm thinking for this 320GB HD.
Use Gparted before the installation to partition the HD and format EXT 4 before installing from the CD.
From reading the forums, I don't believe I need swap since I now have ~4GB of memory - so no swap partition.
1. One primary partition of 12-15GB for PCL installation "/". (This will be a new install from the 2010.07 CD)
2. Another primary partition of about 12-15GB for the dual boot option.
3. ? - At this point I think I now use/make an extended partition for the rest of the drive. I'm not sure if creating this extended partition uses another one of the primary partitions or not?
4. Create another spare partition of 50GB that will be unused. I am putting it here at this location just so that it will be easy to get extra space should I need some for resizing the partitions before or after it at a later date.
5. Create a separate "/home" partition of 30-40GB . (I don't know how much space the virtual machines in VB may end up using or needing so I'm making it a pretty good size - I think?

) (Also, I think I've read were I'll have to learn how to create links from /home to the /data partition below.)
6. Create a "/data" partition of about 80-100GB for my data, documents, files, music.
I plan to just leave the rest of the disk (~100GB) unformatted at this time. I can't imagine ever needing this much space - it now just seems like the outer edge of the universe.

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I'd welcome any thoughts or comments before I get started with all of this. I don't think I'm going to need to create a separate "/boot" partition at the front of the disk but if that is something I should consider please make suggestions.
Thanks in advance.