@Drdirt 

You may want to post this on the global community that is more resposible for Columbia. This specific community is soley for the US region and US support, so the information we can provide is specific to our region.  Everything else is best effort support.  The global communit can be found here:

With the ISP we can't really say until you are with the equipment. As long as the modem has a ethernet port to connect to one of the Deco units you should have no issue using the Deco.  You may need to configure the Deco for the service but that is something local support can help once you have your connection information. 

What is going to be your biggest obsitacle is the walls and floor.  As I am sure you are aware Wireless is radio waves, which are a type of radation and concrete will absorb it.  So where a 2-3 unit system will work for a 4K home with wood walls and floors you might need more that that.  It really can't be tested until your actually in the enviroment.  The testing factor can be what is already being used.  basically you can just about double the service coverage with each one, but again we can't gaurantee performance especially in a concrete enviroment.  Wireless is always shaky in those enviroments.