[strike]I realize this goes a bit over-budged[/strike] but at the time it's one of the best set-ups in terms of power and upgradebility.
Motherboard: AsRock Z77 Extreme6, LGA1155, Intel Z77, DDR3, ATX $160
CPU: Intel Ivy Bridge i7-3770K, LGA1155, 3.5GHz, 8MB, Boxed $330
RAM: G.Skill 16GB (4x4GB) Ares DDR3-1600, 8-8-8, 1.5V $115
GPU: EVGA NVIDIA GeForce GTX 670 4GB Superclocked, 4GB GDDR5, 2xDVI, HDMI, DP, backplate $440
Case: NZXT Switch 810 Full Tower $170
PSU: XFX 1050W Black Edition ATX-PSU, 80+ Gold $200
SSD: G.Skill 240GB Phoenix III SSD, SATA 3, 2.5", 550 MB/s, 520 MB/s, 7mm $190
HD: Seagate 1.5TB Barracuda, 3.5", Sata3, 7200rpm, 64MB $100
OS: Microsoft Windows 7 Home Premium 64-bit OEM $100
Total: $1,805
It doesn't have an SLI but it's really not needed at this point of time (just my own honest opinion so you should ask around and see what other think).
There's a decent sound-card integrated in the motherboard and all the cables you need should be included (get a confirmation from the store). The hyper-threading in the CPU is not supported at this point of time but there's been talk that it will be used in the future so I say it's a good investment.
Unless you plan on overclocking the CPU over 4.2 GHz, the stock cooler will do just fine. Otherwise you should consider buying a better cooler which would cost around $200 depending on the grade.