We don't have a page with all the old versions of our stacks. You can find in the WAMP changelog https://bitnami.com/stack/wamp/changelog.txt and ask us for the version that you want, if we keep it in our internal servers we will send it to you.
In your case, the last version with PHP 5.3.X is:
Version 5.3.29-0 2014-08-19
* Updated PHP to 5.3.29
You can download this version here (md5: 6768f9b63ed3483cd200e4c7622bb503).
I hope this information is useful for you. If you have any other question, please do not hesitate to let us know.
Carlos R. Hernández