the power supply is one of the most important features of the entire system. No you dont need to spend 300.00 on one but get something a little better. I would save 50 bucks on the ram and only get 8gb. Put that money towards a better power supply.But by the looks of it the fancy shiny leds seem to be an important part of your look so I understand how u might want to "gamble" Other wise its going to be a fun build. YAY
I changed to the PSU to the one Ironslice recommended. I believe I need 16gb RAM, I do stock trading and have anywhere from 10-30 different things running simultaneously. Wouldn't having the extra RAM help with that?
I will go with 16gb then. (I do have several very heavy programs I will be running) Also, I am currently running 3 monitors but in the future I plan on running around 6 in the future, figured I would add another GPU then.