DDR2 800,also known as PC6400,that is the highest speed the board supports.As for brands,I like CRUCIAL and even KINGSTON works real good with that board.Goodluck.
Dahak
P5N-D BIOS 1001
C2Q 9550 STOCK (4NOW)
ZALMAN 9700 CPU COOLER
2X2GIG DDR2 1066 IN DC MODE
TOUGHPOWER 850WATT PSU
2X EVGA GTX 280 SUPERCLOCKED SLI
SMILIDON RAIDMAX GAMING CASE
LG 24IN WS LCD 1920X1080
SEAGATE 1TB HD
LOGITECH G15 GAMING KEYBOARD
G5 GAMING MOUSE
LOGITECH Z-5500 5.1 SURROUND SYSTEM
500WATS CONTINUOUS,1000 PEAK
WIN XP PRO/WINDOWS 7 64BIT ULTIMATE