Here is what I chosen, Just to confirm and if there is any better option available:

GA-EP45-UD3P
GeForce 8800GT 256M x 2

Also, 16G ram can be used with any mac versions? I heard that it do not support more than 6G, so want to make sure. I need more ram for windows version, so if thats available for mac too, it would be good.

Any suggestions?

There's no RAM limitation you could hit in Mac OS, but 4GB sticks are awfully expensive.

Yes you are right. I will start with 8G first and then will see if I really need 16G for mac. But in case I need - I just want to be safe

As you own same board, do you recommend to go with this or there are any issues?

Thanks, for your time to feedback.

The only issue is Bios related: you can't use S3 sleep if you're overcocking over about 400MHz FSB. It'll restart every 2 seconds instead of awakening 'til you shut down the PSU. Weirdly, the limit seems to be depending on the CPU, since it was about 378MHz on my former E7200, and it's working at 400MHz on my Q9550 (but not at 500MHz).

If you plan a massive OC, you'd better buy an EP45-UD3R, but not the EP45T-UD3P with DDR3, which doesn't support 4 sticks of RAM properly.

Hi,

thanks again for replying!

Ud3R supports two graphics cards? As thats the basic need of mine.

AFAIK, you can run 4 Monitors from 1 GFX Card. Just get one with 2 DVI Slots and DVI Splitters. My friend uses this to get a 4 monitor desktop. Dunno if it works with Mac though

Sadly, no. Sorry I didn't think about that…