I'm not familiar with Mission other than the name and rep (which are good), but the Paradigm Cinema 100 series seems a little small for a room that size, especially open concept. Is there any reason you are going with small satellites instead of towers or larger bookshelf speakers (WAF, etc)? How high is the ceiling going to be? Also, what will be the usage of the system? Movies? TV? Music? A little of everything? This will help us in giving you advice.
NAD makes good products, but the T748 looks a little underpowered in the space you plan to have it in (40 wpc). What location are you in? It would help to know what retailers or online stores you have as options.
AVR: Denon X3300
F/C/R: Polk RTi A9's / CSi A6 / Speakercraft AIMWIDE 3 / Sub: SVS PB12-NSD
Sony XBR-75X940D, Toshiba HD-A30, Nvidia Shield TV (2015), Xbox One S, PS3
PC: Core i7, 16GB RAM, 512GB ssd + 4TB hdd, GTX 970 SSC