Im not going to answer your question because it depends on too many factors and gets complex really quick.
But, for what you really need to know it just comes down to what systems use what kind of power, your CPU is entirely powered from the 4 or 8 pin CPU power connector which only provides power from the 12 V rail, your CPU uses most of its power from the 12 V rail, it gets a small amount from the 3.3 V and 5 V rails for it's integrated circuitry on the board but most is from the 12 V supply. Hard drives, optical drives, and RAM use the 3.3 V rail and 5 V rails to power their main logic circuits and to provide all the power for the RAM, none of these devices require much power hence new PSUs tend to provide limited power on the 3.3 V and 5V rails but quite a bit on the 12 V rail since that is where most of the power draw is from.
The new PSU won't have any trouble running your CPU.
The RAM draws limited power, especially DDR3, and the main power consumption of an optical drive and hard drive is the motor which is usually powered off the 12 V rail. 4 sticks of ram will pull maybe 20 W, the drives combined will pull maybe 40 W between the 5 V and 3.3 V rails. It is really hard to overload the minor rails on a power supply, most devices with significant power consumption in a computer draw their power from the 12 V rail since there was the change to that being the dominant rail during the pentium 4 era.