The strobe power supply isn't going to work for the LEDs - you'll need to remove this as the LEDs will run off of the 12v or 28v electrical system.
I asked Savvy this question a while ago (ended up buying a strobe power pack because I needed to get back in the air for my checkride, and here's the guidance I received:
For whatever reason, the Piper PA-34 is not on the STC for the Whelen Orion series LED NAV / Strobes. I typically sign these off as a minor alteration referencing Advisory Circular 20-41A in this case. You can review this with your A&P and see if they agree.
I think those units should cover it. You can eliminate the power supplies, but keep the harness and repurpose them to connect the new strobe lights and even keep the synchronization.
