The interlude being Voldon's funeral service would work! That would be the perfect time to introduce some new things you alluded to earlier and a potential wrinkle of my own that I'll list below: 

-Voldon's death would obviously lead to a massive chasm in the Council and prompt speculation as to who would succeed him. I don't think Kira would want the position, so it could fall to either a new character we introduce(because I know we both mentioned in our previous posts about former Masters and Darths buying into the Qyaari) or we could just say that the Elders aren't looking for anyone to fill the seat, moving on with one fewer Elder than before to honor Voldon's memory. In either case...

-Your point about the duo being trained to be Elders is important to this arc, I feel, because Yerbol and Aria are the ONLY two Champions available. I think the Elders probably realize that having them in the classroom full time is nigh impossible, so I'd like for the Council to basically appoint Yerbol and Aria one Knight each as apprentices to eventually add to the Champion ranks. The Knights can accompany our duo on this excursion because, let's be honest, they'll need to get used to the risks of being a Champion in the first place xD. 

-I'd like to bring back Neta as well, seeing as it would be good to have an experienced pilot to guide them once more into unknown territory. I know she'd be excited! 

So, onto the plot points you bring up: 
-I think the logical place to start WOULD be that weird planet Revan was on in KOTOR. Just found out the name of the planet is Rakata Prime...which means if it's named, then it can be found on a galaxy map! Guess they can scour records and find Rakata Prime mentioned in the holos? Or something else? 

-I think Revan and the Exile(whose name is Meetra Surik? Did you know this? Cause I didn't until just now xD) could have visited Prime and left behind their navigation coordinates inadvertently through the material they last went through. Once our duo find the coordinates, they go DEEP into Wild Space and find...

Well, if the Rakata are rebuilding their Empire, Revan and the Exile probably wouldn't be right in the middle of it. Maybe they're hiding out on a world with violent weather patterns similar to Quensu as to avoid detection?

Also, links:
http://starwars.wikia.com/wiki/Rakata_Prime
http://starwars.wikia.com/wiki/Infinite_Empire