There is no selectable PDF/X-1a:2001 or PDF/X-3:2002 feature in Pages ’09, or Pages v5(.2). This also appears to be missing in latest Swift Publisher, and iStyle Studio DTP applications. The open source Scribus does provide in the Save as PDF panel, an ability to embed all fonts, an output profile selector for PDF/X intent, and has a Preflight verifier for Postscript, PDF v1.3 - 1.5, PDF/X-1a, and PDF/X-3 profiles. There is a selector for Output Profile under the Pre-Press tab in Save as PDF. No idea if Scribus PDF output is compatible with your mentioned programs.
You may have to move up to InDesign or Quark to achieve your goals.
The reason neither Pages, or Swift Publisher nor most of the low cost DTP apps do this on OSX is because they use Apple's muddled print output. It almost but not quite outputs to PDF/X-3:2002, and even there there are caveats.
Indesign and QuarkXpress use their own print engines and Scribus uses GhostScript.
GhostScript is available for OSX. I have not tried this so you are in wide open territory, but experiment to see if it fixes Pages' output. My suspicions are that GhostScript may not capture Pages' output before it has already been through Apple's muddled output.
There are other problems with Apple's approach. No specifiable defined colours in Styles. No spot colours, and no proofing. ColorSync itself is powerful but undocumented and difficult to tailor. You can run the end result through Acrobat Pro's Press Check but it only picks up the errors, you are on your own trying to fix them.
The only easy to use, low price DTP application that meets your requirements is Serif PagesPlus, which runs only on Wimdows. You can run this in BootCamp or some other virtualiser.
Adobe lets you effectively hire Indesign CC by the month so may be a cost effective solution in the short term. It is a professional solution but has a professionally difficult interface.
Some reading matter on the subject:
http://pagesfaq.blogspot.com.au/2006/12/how-does-pages-handle-pdf-x-files.html NB the reference to "buggy", hence my description above of almost does it.