I'd go with the OCZ Agility
. It's been a while since I've researched the controller thingies, but I think the Vertex uses an older one. (The Agility is the one targeting mainstream, I think the Vertex is targeting server use.) It shows as faster than the X25-M, but it's only faster in some things. The X25-M is pretty much the most uberest drive all reviewers are comparing to. I'd only recommend the X25-M if money is no object. If money is important I'd say save it and put it towards Eyefinity. The difference in speed will be so small in actual performance that the X25-M won't be worth the price increase for like 90% of the gamers out there.
I would actually recommend against that motherboard. If you look closely the second slot is only running at 4x speed, meaning you can't ever run more than one graphics card. (The site says it can run with Crossfire, but at 4x speed your second card is going to be seriously gimped.) Consider the following change...
Evga P55 SLI 132-LF-E655-KR
$135 post rebate
$170 post rebate (super expensive due to the new 6 gig Sata connectors)
... if you do keep your current motherboard choice, there is no real reason to get that strong of a PSU since you won't really be able to run more than one graphics card.
- - -
I would also make the following (crazy) change suggestion.
Take out the 5870 -$400
add / replace with
$310 (the 5850 gets like 90% of the FPS of the 5870)
Dell P2210H x3
Belkin 6' display port cable
Cables to Go 6' DVI cables x2
Modifications = +$563
Big price change, but uuuuuber.