Sorry, I can only answer the first part of your question. The installer AdbeRdr930_en_US.exe is for all supported versions of Windows; for details see http://www.adobe.com/products/reader/systemreqs/#90win
F.Y.I. there is also an MSI version of the above installer; you can download it here http://ardownload.adobe.com/pub/adobe/reader/win/9.x/9.3/enu/AdbeRdr930_en_US.msi
Thanks for the info.
Any idea why the Adobe download site has 2 separate options for XP SP2 and XP SP3, if the EXE file is identical for both versions?