1.65v memory on 1.5 v mobo

Hi there,
i came up with idea to buy new memory for my PC.
i'm using mobo GA EX58 UD3R. On its manual it say the max voltage for the memory should be 1.5v.
GIGABYTE - Motherboard - Socket 1366 - GA-EX58-UD3R (rev. 1.0)
yesterday i visit corsair.com and search compatible memory for my mobo using memory finder, and came up with these result Gigabyte EX58-UD3R Memory Upgrades - Guaranteed Compatible Memory for your Gigabyte EX58-UD3R from Corsair.
so, i'm no hardcore gamer so i prefer for the CMP12GX3M3A1600C9. the problem is, this memory run on 1.65v higher than my mobo could do. is this fine? can i depend on this result? coz on the highest density section, they suggest me using CMP24GX3M6A1600C9 that have 6x4gb kit, whereas my mobo only have 4 slot?

so, my straight question is :
1. is the corsair CMP12GX3M3A1600C9 fine with my mobo?
2. if i adjust memory profile to 1.65v in bios, then should i o/c my processor too? what would it be? stable? or unstable?

3. which one is better? ddr3 16gb PC-12800 or ddr3 12gb PC-16000

plz help me. this thing make me really confuse..
and, sorry for my bad english, and asking too many question,


ooh, and here's my PC spec :
cpu : intel i7 920 2.66GHz
mobo : gigabyte GA EX58 UD3R
VGA : ATI 5850
PSU : Corsair 450VX
Memory : kingston 2gb (would buy the new one)