IPhoto - Upgrade to Yosemite From 10.6.8 - Question

I have an iMac with 10.6.8 and a Mavs partition.

All is sweet.

However, someday I'm either going to need to update to Yosemite or buy a new computer and I'm concerned that in either event, particularly the latter, my iPhoto will be dead and I won't be able to import a 10 year compilation of photos/albums/events into the new Photos app.

Mt current iPhoto version is 9.2.3. I do not have iLife 11 nor do I have any iPhoto purchases on the App Store.

I did find a link from CNET to iPhoto 9.4.3, but I'm very hesitant to use it since I don't know if it's legit and/or may have other stuff "imbedded" with it.

If I update to Yo, or more likely (since like I said, I'm totally happy with what I have now) - if I need to buy a new iMac, can I get my iPhotos (or more precisely, my existing photos/albums/events) into the new Photos that would be included as part of Yo on a new machine?

Anyone have any suggestions on doing this seamlessly?