Ok guys, ive decided to make the big jump into building my own computer as I have grown quite tired of the stupid Dell Dimension that I am currently typing on. Here is the list of parts that I want to get off cyberpowersystem.com :

CASE : Raidmax Sagitta Mid-Tower 420W Gaming Case w/ Side Panel Window (BLACK COLOR)
CPU : (939-pin) AMD Athlon™64 X2 4800+ Dual-Core CPU w/ HyperTransport Technology
MOTHERBOARD : (Sckt939)ASUS A8N SLI Deluxe nForce4 SLI Chipset SATA RAID Dual PCIE MB w/Gb-LAN,USB2.0,IEEE-1394,&7.1Audio
MEMORY : 2048 MB (1GBx2) PC3200 400MHz Dual Channel DDR MEMORY (Corsair Value Select)
VIDEO CARD : NEW!!! ATI Radeon X1900XT PCI-E x16 512MB VIDEO CARD
HARD DRIVE : Gaming Hard Drive (10,000RPM SATA150) (SATA150 - Western Digital Raptor 74GB 10,000RPM 8MB Cache WD740GD)
Optical Drive : (Special Price) LG GWA-4161 16X DVD±R/±RW + CD-R/RW DRIVE DUAL LAYER (BLACK COLOR)
SOUND : HIGH DEFINITION ON-BOARD 7.1 AUDIO

How does this all sound? It totals a little over $2000 which is my max budget. Anything I could swap out? Anything I should change? Most of these parts are selected off some extensive research with the purpose of having an impressive Windows gaming platform as well as being able to run OSX with stability, support, and speed. Comments would be greatly appreciated.

SATA won't work on nForce3/4.

Yeah I had heard that, but doesnt that just mean that I cant have multiple hard drives? or does that mean that I cannot use any SATA drives at all? I was under the impression that AMD only liked SATA drives. It looks like this motherboard can only use SATA drives? Is that correct? Secondly, if this is true, is there a different motherboard that might be more useable? And finally, could I get a board that would allow me to boot Windows off a SATA gaming drive and then also have OSX on a ATA drive? Is that possible? What kind of workaround options do I have? I know its a lot of questions, but I could really use the help, thanks!

Yeah IDE harddrives are no issue. I don't know where or why you got the impression that AMD only liked sata... but it's wrong lol...

You can have a SATA drive for windows, and an IDE drive for OSX, but OSX won't be able to see the sata drive.

Oh, and the x1900 may or may not have support beyond basic VESA compatibility.

You could just add a PATA drive to this, and use that for OS X, but you won't be able to see the SATA drive at all from the OS X side. Another concern = I have heard of 'stuttering' problems with the AMD X2 processors. If I were you, I would chose a Pentium D (920?) with SSE3, and a motherboard with an intel chipset. My 875P chipset recognizes the SATA controller just fine. In most cases (especially with the mobo and chipset) you want to be as close to the Development platform machines... Take a look at the wiki HCL for 10.4.3. I think the best all-around hardware compatibility we will see from OSx86 is with 10.4.3.

Well I just did some research on the A8N SLI Deluxe mobo and it appears that it has 4 SATA ports and 2 PATA ports. So, does this mean taht I can have both my new raptor SATA drive and my huge 250GB PATA drive hooked up at the same time? And also would I still be able to dual boot the two operating systems (1 installed on the PATA drive, and 1 on the SATA drive)? Thanks guys!

If you're happy with no accelerated video on OS X (doesn't really bother me) then use any motherboard, and get a separate Video card (just make sure it supports VESA 3.0 - most new ones do).
Or you could find a mobo that has the onboard graphics for support in OS X, but also a AGP or PCI-E slot for a card for gaming in windows. (then you would need to switch monitor cables, or a kvm...)
There are ATI cards out there that are supporting QE and CI, and most acceleration. I don't know much about which ones work the best, or how to edit their .kexts to make them work... but there are a ton of posts on that here.

Ok well, it sounds like this mobo will work fine as it offers both PATA and SATA, however, I could find very little info on the compatiability of the new ATi 1900xt card. Does anyone know if I can get QE and CI with this card? What kind of compatiability would I be looking at with this setup? What kinds of resolution can I get with the 1900xt, and also, I have heard that the 1600xt and 1800xt has some great compatiability. Would that be a better choice? From the specs of these two it seems that the 1600 would be a considerably slower GPU and that the 1800 would still be lagging behind the new 1900xt. Is that true? Should I just get the new 1900xt and hope for some new kext drivers and patches?

That's a tough call between 1800 and 1900. The 1800 is a bit slower, but better compatibility in OSX. Who knows how long it will be for better drivers.

I couldnt find too much info about the compatiability of the 1800. Will I get QE and CI as well as OpenGL? What resolutions am I looking at? Finally I am still wondering about the 4800+ CPU. Should I downgrade that?

From the few reports I've heard, sounds like x1800 is on par with x1600 for compatibility.