Advise on this speaker list

I wouldn't worry about the mains & center integrating with subs and surrounds. These units will integrate usually with anything. As Tls49 points out - its important to have the L/C/R's match in a multi channel set up.

I would worry more about how the speakers you are considering will match up with the amp you will be using. Do you already have one? Do you plan on getting one?

If you don't have one, find the speakers you love first and then get an amp that will properly drive them.

That being said, I checked the specs of the mains you are looking at and all appear to be close in sensitivity, 89-92 db and only one is 4 Ohms, the Monitor Audio. So not knowing about the amp, the Chorus 836 would be the easiest to drive, the Monitor Audio 6 or 8's, the hardest. Have fun in your selection process and happy listening.

The minimum distance of a rear ported speaker to the back wall is a good question Dazler and one that may get a lot of different answers. The most common answer that I have seen to this question on various forums seems to 12" and I tend to agree - I would go no closer than this. If you can't get a at least a foot, go front ported.

The manufacturer of my speakers, that are rear ported, recommends a minimum of a meter or 3.2' but in my case, that would be impossible to attain. I have settled for roughly half or 19" and am very pleased with the results.