What Memory is Best for me? 800MHz or 1066MHz

Hello,
I have been doing much research on this site trying to find out what memory to upgrade to...need some help...
I have an Asus Mobo #M3N78-VM and a Phenom II 920 running Windows 7 x64.

I currently have my Processor set to 235x14 FSB and would like to keep it around this speed..
I can NOT Unlock the NB Multiplier so I dont want to go much further than this as to not go too far from the standard 1800MHz...

My question is, would it be better to get 8GB of 800MHz RAM or 4GB of 1066MHz RAM...Im being told my board cannot access the FULL 8GB of 1066MHz?
ALSO...what Brand of RAM as I see so many different reviews.
Hope you all can help me here decide what is best.

As a note...I run FSX on High Settings as well as do alot of Photoshop Editing.

Thanx in advance.

Who told you that the board / BIOS can't address 8GB of DDR2-1066MHz? According to the MB manual that shouldn't be an issue.

I sent an email to ASUS Tech Support just to make sure as I saw mention of this when I searched for the Max Capacity.
He said, "MOBO Supports 1 DIMM per channel for DDR2 1066MHz due to limitations"
Guess all I can do is try it and see what happens, Worse case is i will have 8GB of 800MHz.
I will go for the Kingston HyperX PC8500 and see what happens.

Any other thoughts or comments are welcomed =)
Thanx

A better question is, what in the nine hells are you using to run 8GB of ram, OMW!

You cannot even push more than 3 GB of ram unless your using a 64 Bit System mate, and even then it's REAL hard to push your ram past say 4GB, seriously!

4GB G-Skill 1066 MHz RAM is MORE than enough!
I like G-Skill,for the price, they make good ram, however Kingston recently is remaking a name for it'self again!

Obviously 1066 is better than 800, that's a given.

Hey There,
I am running x64 version of windows 7...

The program that im using which takes A LOT of RAM is Photoshop CS4...
I watched the Performance Monitor as I was working on creating an HDR picture...It used ALL of my 4GBs that i currrently have... =(

Anyway...I was mainly curious if my board will support the full 8GB of 1066MHz as I saw some posts saying it cant???
Thanx for your help...

If you are using over 4GB RAM then getting 8GB 800 Vs 4GB 1066mhz will be better. You could still get 8GB 1066mhz RAM and run it at 800mhz if your mobo complained.

4 x240-pin DIMM, Max. 8 GB, DDR2 1066/800/667/533 ECC,Non-ECC,Un-buffered Memory
Dual Channel memory architecture
*DDR2 1066 is supported by AM2+ CPU only

from the horses mouth

if you look in your manual ( you can download it here http://asus.com/product.aspx?P_ID=ovqEgLFRjnSClhSV&content=download ) on pages 1-14 to 1-17 explains memory for your board