Well money and OS is no problem,i'm just wondering if the extra GB are going to reguire more voltage and wattage,and if they're going to get in the way of an overclocked PC,other than that it really is no big deal as far as the money goes.
The voltage doesn't change between configurations.
The 1T timing of the memory will be 2T if running 4 sticks.
Overclocking results are better with 2 sticks.
There will be a slight increase in Wattage due to additional sticks.
2T is the command rate.
Less sticks better overclock.
Good brands: Corsair, Patriot, OCZ and Crucial.
DDR2-800 the most popular DDR2 memory.
If you have a 32-bit system, stick with 2x1. A 32 bit system will not recognize more than ~3.5 GB.
If you have a 64-bit system, then 2x2 or 4x2 is okay.