my gigabyte motherboard says the standard memory is ddr 400 (3200) and when i go to kingston it gives me a list of memory that will work and they are not 400mhz 3200, does this mean i can use 333mhz of dual 256mb or do they have to be 3200 and 400mhz. whats he best memory for the price, kingston, corsair or others