This topic has been beaten to death, 1 vs two, three, four and so on. Before you ask for opinions, I suggest that you provide us the room dimensions and if it is acoustically treated or not. This will hopefully generate better suggestions, ultimately it’s your room, ears and budget.
Also reiterate if you are dead set on pursuing REL otherwise this discussion much like any other discussions will quickly morphed into REL vs SVS, Rythmik and so on :-)
Here is the latest discussion,