i have some questions i'm very confused

[Shak22]

first off hello nice to meet you guys ^^ i've been reading these forums quite a bit and i've finally ran into a question i could use some help about my computer i got recently nice rig compared to what i had before lol its a

1x AMD Athlon(tm) 64 FX-60 Dual Core Processor
Speed : 2.63GHz
Type : Dual-Core
Internal Data Cache : 2x 64kB Synchronous, Write-Back, 2-way set, 64 byte line size
L2 On-board Cache : 2x 1MB ECC Synchronous, Write-Back, 16-way set, 64 byte line size

Mainboard
Bus(es) : ISA PCI PCIe USB FireWire/1394 i2c/SMBus
MP Support : 2 Processor(s)
MP APIC : No
System BIOS : American Megatrends Inc. 8.12
System : System manufacturer System Product Name
Mainboard : ASUSTeK Computer INC. A8N32-SLI-Deluxe
Total Memory : 3GB DDR-SDRAM
Chipset 1
Model : Advanced Micro Devices (AMD) Athlon 64 / Opteron HyperTransport Technology Configuration
Front Side Bus Speed : 2x 1010MHz (2020MHz data rate)
Total Memory : 4GB DDR-SDRAM
Memory Bus Speed : 2x 202MHz (404MHz data rate)

I have 4 GiG's of ram the burn in didn't show it and my hd 80 gig i didn't have the money to buy the sli cards at the time so i just got a radeon x800 and now im wanting to upgrade my video card's
too two Geforce 7900 gtx but my power supply is 550 antec and i seen alot of things on how much power it use's and things in SLI so im conserned about that im also getting a X-FI soundblaster Fatal1ty cause i heard it helps games and sound would be nice sense i have surround and im running on board sound

but i seen recently this new card XFX nVidia GeForce 7950GX2 1GB 520MHz 2DVI/HDTV PCI-Express Video Card says its like two 7900s stacked on one that uses one pcie slot and less power im just guessing on that

i guess what im wondering is will i have enough power right now im having a heat problem with my prossor its kinda high need to blow it out also could help im just running a 120MM intake and 120MM out take fan i was going to also get two side fans for my case its a silverstone case it has two side fan places and another place to put a fan near the harddrive its a big case and i dont think its getting enough air flow right now im going to buy a few heat sinks

but i was just wondering what u guys think about the power issue or really any suggestions about what i should get and why i've been stuck googling everything the past few days they said those cards get really hot too my house stays warm sometimes also but i can keep it cool ^^

also im using the cool n quite option with the AI stuff on the motherboard and the automactic overclocking stuff which i still dont understand alot about but im tryin to learn as much as i can about what im running to get a handle on everything i just dont want to bottle neck or overheat my stuff its happened before

Thanks for any replies and sorry about the sloppy writing or the lack of info im in a hurry got to be some where in 15 minutes @_@ Thanks again

they'res more too the computer just not enough time to post it all cooling ocing heatsinks Xp-90 looks nice anyone use it does it lower degrees from normal stock copper? this video card power thing has me confused anxity kills also at the time i got my computer was before i heard about the AM2 so i got 939 mb :/ seems like computers hate me sometimes