I am interested to update my 15 year old system !

The older SF speakers were voiced much warmer and darker than their latest models. I would encourage you to listen to their new lines.

Add Harbeth to your list as well. +1 on that recommendation above. 
Newer DACs will help with lower level listening as well as they’re more resolving and transparent than your 20 year old DAC. Depending on what speakers you like, select your amplifier. If you go the integrated route, there are options with built in DAC and or phono stage. The Rega table is fine but offers no VTA adjustment so you’re limited on cartridge choices unless you use optional spacers. 
 

Fun journey! Enjoy!!!

I want to add, pay attention to the warnings above on starting vinyl from scratch. 
Not worth it. @vonhelmholtz nailed it - it will take an uber expensive analog set up to be on par with good digital. Take what you were planning to spend on table and phono stage and invest that in a better digital source. 

The albums you have stored on your hard drive as Apple Lossless (ALAC or AIFF I assume) may not always be the same versions of those albums you would stream from Qobuz. Original in AIFF vs. remastered and or high res on Qobuz for example. 
 

As to the difference between streamers, some of the driving factors would be better quality of parts, better designed and isolated interfaces, better power supply (linear vs switch mode, type of transformer and filtering, etc.) and a better implementation and integration of firmware and hardware. 
There are DACs available on the market that include network renderer either as an option or a standard feature, that makes them Roon ready. That eliminates the need for a streamer, interconnect cable between streamer and DAC and possible power related upgrades you can get sucked into such as external power supplies, power cords, etc. Roon is a subscription based music management service that consolidates your stored music and your streaming services into one platform. It requires you to run Roon Core on your computer and a remote app on your mobile device. You can also use Roon with pretty much every major streamer today with some exceptions, i.e Aurender. 
The network renderer in the DAC typically costs less than a dedicated streamer but in some cases beats out a separate streamer and DAC combos of comparable cost in performance. 
 

All these differences between digital sources will very in degree depending on the quality and price range of the source component(s), the rest of your system, synergy and your ability to hear and identify these differences. 
 

As far as the amp goes, if your Levinson integrated works and sounds fine, I wouldn’t bother getting it checked out by a tech. Just use it you like how it sounds until you are ready to upgrade.
 

@pmm it would not help the resale in any way. If it works, use it if you want to keep it, or sell it in working condition. If it doesn’t work, figure out next steps. 
Don’t fix it if it ain’t broke. Doesn’t add value no matter how you twist it. 

If digital is 1s and 0s then why are you bypassing the Bluesound built in DAC and going to an external dac? What am I missing? Because based on your understanding as long as it’s ones and zeros neither the streamer nor the dac matter, right? But that’s not how it works. I think I explained the difference in my post above. Re-read it please  

Read up on these forums, watch videos on YouTube, read magazine reviews…educate yourself. 
Good luck. 

Hahaha ok. I spent time detailing it for you in my reply on 6/19. Whether you read that or not, or read and didn’t understand it, you came back with it’s all 1s and 0s argument. So my recommendation was for you to get more information from what was already written and available. I don’t owe you anything. Neither do I have time to write a War and Peace on digital playback here. Hence my recommendation for you to put in some effort and educate yourself based on the information that’s already available. But you’re just another entitled snowflake. Remember…no one owes you anything. Pretty simple concept. I’m over and out. Good luck!