Q: iPhoto for osx 10.7.5

Buy an iLife 11 DVD from a source such as Amazon or eBay.

(111364)

By an iLife '11 installer disk from Amazon. That will include a compatible iPhoto '11 version.

Then update it to iPhoto 9.4   http://support.apple.com/kb/DL1589

for compatibility with Photo Stream.  You will have to run the iPhoto Library Upgrader to upgrade your iPhoto library, before you can open it in iPhoto'11.  See:   iPhoto '11: About the Library Upgrader

If you do get an iLife 11 disk and install iPhoto it will be v9.0. You can run v9.4.3 so you'll need to use the following updaters to get to it:

1. update to iPhoto 9.2.1
2. update to iPhoto 9.3
3. update to iPhoto 9.3.2
4. update to iPhoto 9.4
5. and finally to iPhoto 9.4.3