I think it depends on how obsessed you are with absolute best SQ. In my opinion Sooloos into ID40 is pretty much equivalent to spinning discs in the 808 and is a little better than SB Touch into the 808 via coax and upsampled there. But the difference is not like night and day - if I listened to both options on different days blind I doubt I could tell the difference reliably. So for me it was a peace of mind thing - I wanted the convenience of streaming and I didn't want to be fretting about what I was missing with the SB. In this case, obsession = big bucks (which I do not regret for a moment, because I have stopped listening to my streaming solution and I'm listening to my music).

I agree with Ronnie - try streaming with a low cost solution first and see how you get on. If you rip to FLAC then you can import those files to Sooloos if you do decide to go that way at some time in the future.

In my experience streaming solutions are unlike other kinds of audio in that the SQ differences between modest cost and cost-no-object high-end systems are smaller than, say, between CD spinners or analogue sources; and hugely less than the differences between good and excellent amplifiers and speakers.

BTW, the ID40 comes built into the 808.3 as standard.

MC200, Twinstore, 808v6/ID41 -> DSP8000SE (+ SB Touch, Sony BDP-3300, SKYHD, legacy cassette player)
2nd system: MC200 analogue out, Linn LP12, SB3 -> Quad 34 -> M60 rosewood
F80 (Rubino Micallizzato)
F80 (Rosso Corsa)