1st question? why not use the ASUS A8N-E board is only like $94.00
unless you plan on buying 2 2crossfire enabled video cards.......
the X850XT is the better card, has 4 more pipelines available, has higher core/clock/memory and will outpreform the 800GTO card......
regardless if it is ATi / Sapphire / ASUS ---I have used all three of these branded Radeon cards and have had no glitches from any of them, except a card I gave away was a 9200 64 meg radeon, gave it to a player on the boards here, it helped him improve his FR, but he was already even worse.......that 9200 card was prob worse I have ever used as far as finding the corrct drivers to maximize its ability........
I have a Sapphire Ati 9000 atlantis Pro 128 meg 4x AGP and a TRUE Ati 9800 Pro 128 meg 8x AGP cards along with a 9000 sapphire ati 64 meg and all work great for what they are...
newest cards are ASUS X850Pro ( has 12 pipelines and the other 4 are unlockable :-( )
and an ASUS EXtreme X850XT both 256 meg, both rock and don't skip a beat.....
only GeForce card I have in use is an old Mx400 64 meg something or nother, works great also, was a gift from a squaddie.....
anyhow, I would go with the Sapphire X850XT, Karaya.......my opinion more for ya money......
I would opt for the A8N-E 939 socket MB though, unless u plan on using crossfire down the road sometime, or step up to the A8N Premium or A8N Delux ( one is like 114.00 the other is like 153.00<---deluxe) if you want to use the dual SLI stuff...better yet go A8N-E Deluxe 32bit Sli nforce4 thingymajiggy card ( 224.00 ) and cover all bases......
as for the opteron, can it overclock like the 3700+ can, 3700 is capable of running at FX57 speeds without an elaborate cooling schemes.......
I like the Antec powersupplies as well.....using in 2 different PCs the antec TPll 550 watt trupower 2.0 Power supplies, the big 120mm fan is quiet and even helps keep pc running cooler......( they run around 80 to 90 bucks though )
good luck , Karaya
need to add: Whels has been building PCs for as long as I remember him playing AW back in mid 90's, I will usually run my setup for a new pc by him, since he stays up to date on most all these things, and he has stopped me from buying 1 or 2 things before I made a BIG BOOBOO