Get "Windows XP Home w/SP2". Once you install that go to Windows Update and install all the updates, especially the security updates. You will then have the latest and greatest. I wouldn't get too hung up on model numbers.
and life goes on...
Where is a list of the model numbers for Windows XP Home? I am trying to purchase another copy for my latest build and noticed that there are many different model numbers for sale. I would like to see a list of these different models so that I may purchase the best for my needs. Example N09-01528