Reddit mentions of Roku Ultra - HD and 4K UHD Streaming Media Player with HDR, Enhanced Remote with Voice Search

The 2016 Roku Ultra (4640) has optical out and will transcode DD+ to DD.

https://www.amazon.com/Roku-Ultra-Streaming-Player-Enhanced/dp/B01M05030B

The Roku Ultra 2016 edition (model 4640) is the last one they made with optical audio port.

https://www.amazon.com/Roku-Ultra-Streaming-Player-Enhanced/dp/B01M05030B

You could also use a hdmi audio splitter thingy like this:

https://www.amazon.com/Musou-Extractor-Optical-Splitter-Converter/dp/B06XDNJ6RM/

With 58 reviews it has 2.7 stars which is why I posed the question.

https://www.amazon.com/Roku-Ultra-Streaming-Media-Player/dp/B01M05030B/ref=sr_1_1?s=tv&ie=UTF8&qid=1478210456&sr=1-1&keywords=roku+ultra

The Roku Premier+ and Ultra both support 4k HDR and Dolby Atmos pass through over HDMI.

Edit: Just realized you are in the UK, I don't think those newer Rokus are available there unfortunately :(
It sounds like you might be able to import one and get it working from what I have read online though.

Edit 2: Looks like it is available from 3rd party sellers here - https://www.amazon.co.uk/Roku-Ultra-Streaming-Media-Player/dp/B01M05030B

Unfortunately the Apple TV doesn't work like the Roku. It still works like any other streaming device but you can't program your favorite channels.

Basically the favorite channels for the Roku act like your cable/satellite favorites. You can make custom activities (ex. Watch Netflix) and set your starting channel.

You can still do this with an Apple TV but it takes extra programming and might not work as well.

I'm not aware of any other media players that have these abilities at the moment.

The new Roku Ultra has 4K and HDR and it goes for $130:
https://www.amazon.com/dp/B01M05030B/ref=cm_sw_r_cp_api_iA9yyb3CE4HZN

The Premiere+ goes for $100:
https://www.amazon.com/dp/B01LXUZPQU/ref=cm_sw_r_cp_api_7A9yybTJPPG44

Both seem to be on sale on Amazon.