Streamer ugrade options please

Hi Thanks for reading.

I have a dune d1 streamer which i am using for playback of music and movies from a usb 3.0 hard drive.
The dune has hdmi out which i am connecting to a screen for the picture, and the dune has analogue stereo output which i am connecting to a power amp for the sound.
The sound and picture is good but i am wanting to upgrade to an audiophile set up with 5.1, so am thinking of purchasing a high-end blu ray player which has 5.1 analogue outputs, also hdmi out for the picture.
Can you recommend such a blu ray player. I need one with a volume control as the power amp i am using does not have that, and upmixing / downmixing functions, audio eq etc. The blu ray player must be able to decode dts ha ma and dolby true hd
I would like to purchase an older model as brand new releases tend to be expensive, the price drops rapidly when manufacturers release a new model and they discount older models to get rid of them.
Alternatively, a 5.1 streamer would do the job fine. I have looked around but cannot find one. Can you recommed.

Many thanks.
That is a lot of requirements, and the market for high end players is shrinking.  I would rethink your needs
The Oppo 105 is likely your best bet for functionality and cost.  There's actually a BDP-105 on audiogon now that's been modified with linear power supply and upgraded fuse.  Price is $558, which is extremely low for this item.

Otherwise, maybe Panasonic DP-UB9000 if you want something new. 

I don't know of any 5.1 streamers that have full 5.1 analog outputs.
Your requirement list is long and things are looking bleak for the blu-ray market. The upcoming playstation 5 release from Sony is projected to pretty much kill the rest of the contenders in the Blu-Ray market.

Oppo would have met your needs, but, unfotunately, they are done. It was a sad day when my Oppo broke down.

Your best "audiophile" option at the moment is a Yamaha BD-A1060 blu-ray player (plays blu-ray audio, sacd 2.0/5.1, hdcd and everything else out there). It was designed to compliment their Aventage series receivers and surround preamp processors. It has balanced output stages, 2 channel out, both balanced XLR and rca analogue out, decodes all your surround formats, etc. It sounds phenomenal and gives Oppo a run for its money!

BUT, you would need a surround pre-amp processor or a receiver with 5 channel pre-outs though as it does not have a volume control or 5.1 analogue out.

You may have to move fast on this Yamaha blu-ray player because it is expected to be discontinued very soon! And then some A-hole will try to sell his used abused unit to you for 4 times more (you can see that going on with used Oppos).