Yes, 4 studio monitors + sub for surround is a good start
Detailed review of the Yamaha hs7:
https://www.audiosciencereview.com/foru ... tor.19761/In the same price class, JBL 308p seems to perform better:
https://www.audiosciencereview.com/foru ... iew.17338/I have Genelec 8020 (reviews of the related 8010 and 8030 here:
https://www.audiosciencereview.com/foru ... iew.14795/,
https://www.audiosciencereview.com/foru ... iew.16866/)
They are small size (much less visual impact) and among the best in class, but they are a bit more expensive too.
Behringer 2031A appears to have copied an older Genelec design, so they can be quite good indeed, but they are much bigger than the Genelec 8000 series.
Yamaha HS8 goes down to 38 Hz. Probably just good enough for playing 16' stops (which go down to 32 Hz) but for 32' stops you might want to have something bigger, if room allows. REL and SVS are trusted subwoofer brands. However, if you are in an appartment and have neighbours, you might want to exclude a sub from the package because low frequencies travel very far.
Once you are setting up the speakers consider the following:
Front speakers are best placed in an equilateral triangle with your listening position, at appr. 1m distance (assuming you have nearfield studio monitors), at or slightly above ear height, tweeters pointed to the ear, no obstacles and keep them as far away as possible from any surface (of course you probably will have to make some compromises). Same for the rear speakers, except that you can place them to your sides, and somewhat behind you.
In many rooms an excellent setup is to place your console at a 45' angle in a corner. Front speakers on top of your console. Rear speakers mounted to each of the walls at your side. Sub are best placed in a corner, and you best have a symmetrical arrangement of walls and sub respective to your listening position. So a very logical place for the sub is the corner space that remains behind the console. As an extra advantage, the large sub cabinet will be out of view.