Something that is very important to me when setting up a system for myself or others, is how does the listener interface with the system? Meaning what actions, controls, or apps are required to use the system. I find that an easier and nicer looking/feeling interface makes for a much more enjoyable listening experience even for a nerd like me. And the average person may not even use the system if it isn't easy.
For instance how will you select music to stream? An app on your phone or tablet or TV? A program on your computer? What capabilities must this software have? Will volume be controlled via the app or do you want a physical remote control? I assume you don't want to have to walk over to your system to turn it on and off, so do you want to do that with a remote or an app or do you want it to happen automatically? If you want a remote, do you want it to have transport controls for your streaming? There are many different means and methods for getting the usability you may want but if you buy hardware and software without considering these things you may end up with a system that's not as enjoyable.
I recommend having room correction and multiple subs in any and every system. It goes a long way towards higher fidelity and listening enjoyment. In my systems I usually have multiple sources I want to use such as TV, music streaming, LP's, and Tuner. For this reason I use hardware based DSP components from miniDSP so that I can have room correction and corrective speaker EQ with all of my sources. My miniDSP's have 4 outputs so I can crossover to and individually EQ 2 subwoofers. They also have Dirac Live room correction built in which works great in my experience. Other great hardware based room correction systems I know of include Audyssey MultEQ XT, Anthem ARC, and Genelec GLM. Alternatively you could use your streaming software to apply EQ which allows you to use less expensive hardware. Roon and Jriver a couple I know of that can do this. This then only allows you to apply room correction to one source. It also is not automated so you have to learn to take measurements and use a couple pieces of software without a screen guiding you.
The Genelec system actually looks very neat to me. Just about everything is built into the speakers so you don't need a piece of hardware for crossovers, or D/A conversion or amplification. From what I understand, GLM is pretty easy to use and you can use it to control volume of the system. Plus I think their speakers turn on automatically when they sense a signal.