The difference between bronze and gold is efficiency. While this might sound as an important factor, this factor does not concern you since you're building your PC that does not draw a lot of wattage. If you were to build a system with 2 or 3 GPUS efficiency will become a factor. But in your case you don't need more than bronze unless you really care about nature and you'd want to avoid the waste in power (which is around ~20% on maximum load).
The difference between bronze and gold is efficiency. While this might sound as an important factor, this factor does not concern you since you're building your PC that does not draw a lot of wattage. If you were to build a system with 2 or 3 GPUS efficiency will become a factor. But in your case you don't need more than bronze unless you really care about nature and you'd want to avoid the waste in power (which is around ~20% on maximum load).
As for ram, I'm currently using those in my current rig: http://www.amazon.com/Corsair-Vengeance-Desktop-Memory-CML8GX3M2A1600C9B... and I'm using this version because I have a huge CPU cooler, but you should get this instead: http://www.amazon.com/Corsair-Vengeance-PC3-12800-1600mHz-CMZ8GX3M2A1600... The fins will provide some better cooling to your ram sticks.