What do you descedirem be best to follow

Hello everyone I'm from Brazil and some time I have been thinking about building a residential soundsystem . I would like the help of friends forum to which way to go . I have 2 speakers 18,800 rms 99 DB . I buy 2 more 18,800 rms 99 DB and make 4 cubes ? Or do 2 scoop design Rog Mongale and use the 2 I have? The speaker is this link www.oversound.com.br/produtos/alto-falantes/pro/sub-800/ To process the residential soundsystem have a digital processor DBX260 . Grateful to everyone from the answers already .