What's my ideal music server? Read and recommend please

The MDX board is superb. It’s been fitted in my M1 since July 

I wonder if this is doable and a viable solution- continue to use my MacBook Pro and use a Bricasti M5 renderer between my laptop and the dac 

So just how pricey are these Bricasti products? (M5 in particular) There literally isn’t a dealer within 1,000 miles of me and their website doesn’t even show an MSRP on any of their products. As a career marketing manager, I have a very negative initial impression of any company who does much of their business exclusively on the net, but intentionally does not post an MSRP.

I have a bricasti dealer a reasonable distance from my home. List price is easy enough to find on the internet any by and large companies that don’t direct market don’t show prices on the internet. One of the advantages of living just a bit north of NYC- just about anything is available within an hour or 2 drive at most. Heck, I can get to McIntosh Labs in 3 hrs. 

Zavato
Just get rid of your mac book pro.  When I went from my MacBook to the Sonore Signature Rendu SE the improvement was HUGE.  This unit acts as the renderer or client.  It also handles the streaming.  My Small Green Computer is where my music collection of 7TB lives.  It has an one board drive for ripping CD's.   It is similar to a Roon Nuc but has better components and was made to my specifications with a 10 TB Solid state hard drive.  The server and the renderer run proprietary "Sonic Orbiter" software which integrates the two units flawlessly.      For playing music the combo runs Roon which is the best platform.   My experience with setting up this system was truly plug and play.  Support from SGC and Sonore has been very good.  
This digital front end cost about $8K.  I run it thru a PS Audio direct stream DAC.  This fairly "humble" front end  is able to make my Nagra HD electronics and Wilson XLF speakers truly sing.
I can state the following with certainty:
1.  The best server is the Taiko Audio, bar none.  ($30,000)
2.  Aurender W20SE is probably 2nd in sound quality, but doesn't do ROON  and I LOVE ROON.  A friend loves his N10.
3. Innuous Statement, Antipodes EX/CX combo, Wolf Audio's higher end are all  excellent choices.
4.  In the end I chose the SGC Server as Andrew was willing to put in 10TB SSD for a reasonable price as I have a large music library,  and  the Sonore Signature Rendu SE because of excellent reviews.  (I spoke with one of the reviewers and he purchased the Sonore)
5.  Any of these options will be an obvious improvement in SQ, reliability and ease of use over the MacBook, especially if you get ROON

BTW you have a great DAC.  Almost bought one, but just purchased a Rossini instead.