Appamanna
New Head-Fier
Personally I still wouldn't recommend the SR35 due to the smaller soundstage compared to other players in the price range. And the massive soundstage is one of the big party pieces of the HD800S and the main reason to go for the HD800/HD800S so why reduce it. Other options like a Shanling M6 Ultra or FiiO M15S if you can stretch for them would be a better option with a way smoother user experience and (in my opinion) better sound quality.
Edit: I see you've made a choice, and the same one I've made.
Although I've had some complications with the delivery getting lost, so I'm waiting for the store to get stock again. Which should be this week.
I've actually made a new choice - the Astell & Kern PA10 portable amp. I'm finding it to be demonstrably better than the Fiio M15s, which is going to be returned. For a source, I'm using an old phone with a Lotoo PAW S1 dongle that I already had - it sounds great with the PA10.