What exactly do you mean by everything? Do you need an OS or keyboard and mouse in the $1,000?
If you need a monitor, you cannot afford the GTX 470 or two of any decent GPU. It's just not going to happen with this budget. Monitors aren't that cheap. You'll also likely need an OS ($100), which really puts a dent in the budget.
Here's a great $1,000 build, with the OS and a little room for a mouse and keyboard:
That's not a good combo. Thermaltake PSUs are low quality. Also, the new GTX cards are mostly considered a waste of money as they perform too close to the cheaper ATI cards (the 5850 and 5870) but are priced too close the card above them. The 470 only offers a slight performance bump over the 5850, but is only $30-40 cheaper (less with great combos) thant he superior 5870. They just aren't good buys at their current prices. If they were $20-30 cheaper, they'd be perfectly placed.
I would be remiss if I didn't tell you that MMORPGs aren't very intensive. If that's all you play, the very first build (the X3/5770) would be more than sufficient. The X4/5850 and X3/5850 builds ares more towards the beginings of hardcore FPS gaming builds.
You're budget won't allow for a good Intel based build. The cheapest decent Intel CPU is the i5-750, which is already $40 more than the X4 955. The Intel boards are a good $50-75 more than AMD boards (possibly more, depending on the deals). The Asus P7P55D-E Pro is the i5 equivalent to the board above, and costs $190. That means you'd be stuck with the 5770 and wouldn't have much to show for it.
Frankly, unless you've got $1,500 or more for the tower alone (no OS, no monitor), you'd get a better gaming build by sticking with AMD. The only exception is the $300 hole between the price of the HD 5870 and HD 5970, which allows for the i5 to sneak into a build below that budget. However, that's still a $1,200 tower.
Besides, you mentioned that you want something that has the potential to be upgraded. Intel has already announced that they plan on moving to two new sockets in the next year (LGA1155 and LGA1365). That means there won't be any more powerful CPUs for the current sockets.
Thx Mad, I think I made my decision. I posted another thread and my only final doubt is on the mobo. I wanted the Asus crosshair (so f awsome) for possible future cf with a 2nd 5850 but I'm not sure what to do...
The Crosshairs are overrated. The higher price doesn't get you any additional features, so there isn't really reason to pay more than you need to.
The board I recommend also allows for adding a second 5850 later. If it's the 8x/8x speeds you're worried, about it's a non-issue. Tom's did a review a while ago comparing 16x/16x Crossfire to 8x/8x and found that 16x/16x only gave a 4% performance boost and would only be noticeable when you use 5970s. Given the huge price increase to get 16x/16x, it's not recommended to spend that much to only get 4% performance.