Options are being looked at on getting more tuners, but there are no plans that I know of to produce any more at this time. You may never be able to get one - I don't know. I hope no misguided soul decided to buy out all the tuners and stockpile them somewhere.
2. Hook it up to another head unit and use that units tuner. It will sound fine. I guess if you are really handy with electronics, you could possibly wire in another extenal tuner???
I hope we are able to somehow get everyone a tuner that wants one.
Sean