I have two pioneers that put out 800 rms. you can hear mine pretty well and i only run them on a 600 watt amp. the problem with SUV's is that the sound travels differently than in a car. In an SUV you are pretty much the only one who hears it (other than maybe the cars on the sides of you). In a car the sound travels foward because they are in the trunk. That way people on the sides as well as the people in front of you can hear it clearly. 800 should be fine for you, subs sound really good in SUV's, just make sure you get a good amp, not some crap brand. have fun with it
