As for the graphics cards I'll be going with 2 X 3870 since I hardly use AA or AF (I probably even spelled them wrong just now)
I forgot to mention (though it is pretty obvious this will be a gaming build and I'll use Vista Home premium (for more than 4 Gigs) also by the time I make this build the prices of the items will probably be lower and Vista might actually make sense
your original mobo is not an Xfire(ATI) board but rather a SLI(NVIDIA) setup. If you want an ATI board go with a p38 or X38 setup. If you stay with the board you've picked then think of some SLI nvidia options. by the way your rig will be close to mine. I posted my tread a while ago.
I think the WS stands for 'work station' but I'm not real sure. I believe there are more bios and overclocking options with the Maximus and with what you're wanting to do, it'll perform better. Again, I haven't used either board, so this is just guessing on my part, maybe someone can confirm this.
Keep in mind that ASUS is not very newbie-friendly in terms of overclocking. There are some weired-s settings you can't figure out on your own. Call it Engrish. i.e. we say vdroop (voltage drop under load), they say load-line. Gigabyte has X38 boards also, but they're newbie-friendly.
WS stands for wireless, I believe. The similiarity is that they all have built-in wireless adapters.
It's a toss up between the P5E & Maximum. Maximum may be better in terms of overclocking, but then again, it has MORE confusing overclocking settings in bios. ABIT being the most difficult.
The purepower isn't good enough. Go with Toughpower or other tier 1/2/3:
If an Asus has wireless they add WI-FI to the name, I thought I read somewhere that WS meant work station. This was a while back and I don't remember what site I was on. I'll see if I can track this down. Just checked that WS board does not have wireless, it has 2 lan ports.
I found the WS board on the Asus website; http://usa.asus.com/products.aspx?l1=3&l2=11&l3=572&l4=...
The bios may be harder to understand if you're not familiar with bios settings and overclocking, the WS may or maybe not quite as advanced as the Maximus.
You can download the manual of the Asus board(s) from there website, there are download links with each board listed. Be warned their website is S-L-O-W
There's a good thing about difficult overclocking since you're given more options to fine tune your overclock. You have more control. On the other hand, you have a higher chance of screwing up an overclock. The manual is Engrish at best. Google your board + "overclock" & look at others' settings.