Hey, new here! sick of having laptops die on me, so i'm building a desktop for the first time ever. Think i have a decent build here, but could use some pointers. It's going to be used for a bit of everything including gaming, and i want it to last me as long as possible.

Right now i'm unsure about a couple things, the PSU for one. I know it's overkill, but i do plan on gradually adding a couple more hard drives, and maybe xfireing another 6950 at some point. Is it still overkill at that?
Still a little unsure about the gpu, i could probably spend the extra 100 and xfire a couple 5870s, but id rather take a small performance hit, go with one 6950 for now, and have the option to upgrade at a later point by sticking another 6950 in. Is it worth it to do that..? What would the performance difference be between the two options?
The watercooling system- absolutely new to them but been recommended this one, does it cover my cpu, gpu, or both? Is it compatible with 2 xfired cards?
Also, the case is eATX based, i think that board is ATX standard right? Will it fit?
I need a monitor as well, what would i be looking for to match a system like this? Not looking to spend a massive amount in this department, and a 24 inch one would be about right..
Other than that, any tweaks/advice? Much appreciated!!

Right now i'm unsure about a couple things, the PSU for one. I know it's overkill, but i do plan on gradually adding a couple more hard drives, and maybe xfireing another 6950 at some point. Is it still overkill at that?
Still a little unsure about the gpu, i could probably spend the extra 100 and xfire a couple 5870s, but id rather take a small performance hit, go with one 6950 for now, and have the option to upgrade at a later point by sticking another 6950 in. Is it worth it to do that..? What would the performance difference be between the two options?
The watercooling system- absolutely new to them but been recommended this one, does it cover my cpu, gpu, or both? Is it compatible with 2 xfired cards?
Also, the case is eATX based, i think that board is ATX standard right? Will it fit?
I need a monitor as well, what would i be looking for to match a system like this? Not looking to spend a massive amount in this department, and a 24 inch one would be about right..
Other than that, any tweaks/advice? Much appreciated!!