BW 801 D4 or BW 802 D4 + 2 subs

Can you tell us about your listening room...size, furniture, acoustic treatments, type of floor?

I would always pick the alternative that goes with subs. There are many good reasons, but one of the main one's is the ability to put an EQ in line with the subs.  That plus a high pass filter will almost always give you the chance to get better overall bass response in a room than trying to get the same from just two large main speakers.

Then there's a litany of other benefits, like increased dynamic range, lower main amp stress... etc.

I recommend the use of the AM Acoustics room mode simulator to help you place your speakers and listening location, careful measurements and GIK soffit traps in the corners if needed.  If you do all this well you are going to have a very difficult time finding a system that performs better in bass speed, impact or system dynamic range and clarity.

@rick_n 
i´m building the house. will think about treatment later

The room is 7meters x 12 meters  (3.5meters high)

the speakers will be placed on the 7mts wall
there will be a fire place between the speakers.

floors will be porcelain tile, with mat close to speakers.

@erik_squires 

do you like these subs?  (not sure about the s510 ou s812)

or recommend other brand?

about 5-6k to spend on subs.

With a fireplace between the speakers and porcelain tile floors  it's good that you're going to think about acoustic treatment. You're gonna need it.