Josema

I bought a Onkyo TX-RZ740 with 185 watt per channel and I want to set a 5.1.2 home theater system at home in a room that is not very big (5m/16.4ft x 6m/19.7ft). I have doubts in which front speakers and subwoofer I should buy. I've been thinking about RP-8000 and RP-6000. I don't know if the first is too much or the second too low for the Onkyo characteristics. Also, for the sw I'm in doubt between R-115sw or spl-120. As you can see, my knowledge is very limited so any help would be appreciated. Thanks!