Transition Data from One Magento Server to Another

First off, I’d just like to say thank you to this community for the help, both with my last question (around caching) and for taking the time to answer such questions in general.

I am helping to transition a Magento store from an old server to a new – making some much needed infrastructure tweaks along the way. I’m almost there, but I’m wondering how best to transfer the data from old to new? I know there are import/export options, is that the way to go? Here is one constraint that may or may not make things more difficult: the “old” store is working well, however it is in production with little in the way of a contingency plan in the event of failure or setup related issues. Long story short, I would prefer not to install any additional extensions, etc. on that platform to keep it in good form until the new system is ready to replace it. Dumping data from the database, etc. would be no problem if that’s an option. The two installs are close enough in versions that there should be little in the way of compatibility of data between them (I’m thinking).

Primarily, I’d love to be able to transfer products, categories, customer data, and sales. If anyone has any helpful thoughts, I’d love to hear them.

Thanks in advance.