I just realized you may be able to use the current suite. Or, that is, get an older version of CC that will run under Yosemite.
When you purchase CC, you first installer the Creative Cloud manager. Launch that, and in the preferences, there's an option to be able to view older versions.

Once you turn that on, you can choose older CC installations.

While it is true Adobe will not directly sell CS6 anymore, you can see it's still available through CC. It's still monthly, but it's there. Of those, I use Encore CS6 since it's the last version of the DVD/Blu-ray disk authoring software they released.
Anyway, you do have options that will run in Yosemite. Check with Adobe to be sure which is recommended for that version of OS X. But since Yosemite was released in 2014, I would think any version from the original CC to possibly CC (2017) would run. I would suggest using the newest one you can for the best compatibility with your clients and features.