Digital Audio from Raspberry PI 2

Hello all,
let me introduce myself. My name is Vincenzo and some day I discovered this beautiful product for my Raspberry PI 2.
I have to say that the software is very fluid, and see the movie in H264 gives me great satisfaction, so much so that I’m thinking of replacing my Apple TV second generation with the Raspberry PI 2
Only small defect I find in this Raspberry PI 2, is the audio output which I noted to be 3.5 mm while on the Apple TV I have the digital output.
I noticed on Amazon several solutions.
The most economic is to convert the output of 3.5 mm to the RCA output, in fact, with few money you have to buy the converter. This solution, however, I fear that I do not have much power to get to the amplifier.
Another possible solution, is to purchase the digital form to attach to the RASPBERRY PI 2. If I understand it the most interesting, should be those produced from HiFiBerry. But they work with the OSMC ? There are particular problems ?
The last solution, instead, consists in the purchase of the HDMI Extractor, where the price is equal to the digital module.
What is the solution between the last two recommended in order to achieve a great sound output from the Raspberry PI 2?
Thanks to all.