Your power supply shouldn't be substantially loud, if it's a half decent model. The RM series units are not great quality, unlike the RMx and RMi units. The TX units were good quality, but those are older units now and most of them are probably near end of life status.
If you want a very good, really quiet unit, I'd suggest either of these. I've used both, and currently am using the G2, both of which are made for EVGA by Super Flower, and they are both quiet and excellent quality.
http://pcpartpicker.com/parts/compare/evga-power-supply-110b20750vr,evga-power-supply-220g20750xr/
The only reason your display should flicker or have problems due to the power supply would be if there was a problem with the unit OR a problem with your graphics card. Knowing your full system specs would be helpful.