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.
Peter
Some reading matter on the subject:
http://www.prepressure.com/pdf/basics/pdfx-1a
http://support.pixelmator.com/viewtopic.php?f=3&t=10355
http://en.wikipedia.org/?title=PDF/X
http://help.adobe.com/en_US/acrobat/X/pro/using/WSb2f1a50375cd48d3-1f36d19412ada 208ceb-8000.html
http://www.belightsoft.com/products/resources/spsolutions.php
http://www.pdfxreport.com/doku.php?id=en:tools
http://www.planetpdf.com/creative/article.asp?contentid=6541
http://pagesfaq.blogspot.com.au/2006/12/how-does-pages-handle-pdf-x-files.htmlNB the reference to "buggy", hence my description above of almost does it.