lol, can't help you too much, I've built a system for someone else (a budget/gaming computer) with a x2 (Phenom 555 Black edition) unlocked to a quad [luck!, though no noticeable affect in games] with a Geforce 450, he seems more than thrilled with it, his words; "it's like I never had a computer".  
This comes from him playing on a i3, Geforce 320M laptop.

He only had $500 to spend, I think it finished around the $450 mark.

A 460 ATM is a  mid-ranged card, it can max out most current games with relative ease, and doesn't break the bank either.

Personally I've never seen the appeal of SLI/crossfire, because of several factors;
Not all games support more than one GFX card (less and less as time progresses though)
//Better Motherboard (2 PCIE x16 slot motherboards cost HEAPS, vs just a regular 4+1 phase single slot)
More power consumption == better PSU (again increased cost).

Although I see the prospect of saving a few $$'s on a couple cards to flog a more expensive one, but single card solutions can [AND DO] the trick (that is MAX out games).

Intel or AMD debate flings off again, AMD actually does perform comparatively in games! (from what I've seen, NOT the system I built, but other people's reviews/opinions).  

No doubt any i7 will eat any amd's variants for breakfast, but depending on how much you wanna spend, you can always goto the extreme angle.  
Watch it with the CPU, again not all games can utilise all cores, I believe most games aren't designed to utilize more than 2 cores anyway.  But other background applications will benefit.

SDD's may actually outperform a raid array of several hdd's since the latency of each hdd cannot be overcome. but total throughput is increased.  [pointless fact in your case]

SDD's provided the case is equiped with a 2.5" bay, or some spacers, it's as easy as counting to ten to install.

DDR3 1600?, you planning to O.C.?   if not there is no real point, save your pennies and just get nominal 1333