Well, that's a very nice system, Hyde, and the fact you'll be able to use Ivy Bridge CPU's is really cool. I don't think you could be disappointed with it at all.
The case is definitely nice; I had one but much older version. Yours is an improved one. Silent, well made, clean look. Very good quality/price ratio. With silent fans that should be very cool. (If you're looking for silent fans you'll probably have to test a bit unless you're lucky; reviews are questionable et reputations too.)
Your Corsair AX is made by Seasonic. (Corsair PSU's are made by either Seasonic or Channel Well Tech (CWT)). It's a Seasonic "X" series. Normally, most excellent stuff. I could have bought one. The Antec I use is made by Delta from their top lines too, a company making highly reliable server PSU's.
Water cooler: you picked the very one I would have picked myself before the Antec (Asetek) was released. On a i5-2500, its should be just fine. The only thing is that the tubes are a bit rigid compared to Antec's, shouldn't be a big deal though and it only matters when you mount it.
CPU: nothing to say! Excellent and more reasonably priced than mine.
RAM: 16 GB... so you're a RAM sicko too, hey?! I just added the last module to my system, so I now work with 4x4GB modules. Running the last versions of FC's Dreamworld Cheetah graphic engine (the one in AoC and more or less TSW) at 1980x1080 and close to full options uses like 28% of that RAM. Of course, a lot is done by the graphic card but the CPU and the system RAM have to prepare the work for the graphic card.
120GB SSD... I hate you! I didn't know I would be that happy with a home SSD... and now my 64GB needs a companion. I'm going to slaughter the money pig again -who hasn't recovered yet- and get a Crucial 256GB asap. It's just awful... SSD's are like a drug. You get addicted. You are working on a very nice Western Digital Caviar Black in the same system as the SSD and you are like "WTH... why does loading this software take FIVE seconds... it's unbearable! Five seconds, what a shame! and WTH is that painful noise?!" We're spoiled children...
You didn't say what SSD bran you picked but TBH, as long as the SSD supports TRIM for better reliability over time, I'd say that any SSD is a major upgrade over any regular HD, even if the very last series by Kingston (Hyper X SSD's) beats every other model.
MSI MB... I never forgave MSI to be unable to fix a boot issue that sometimes happen on my old Neo2 Platinium MB (AGP graphic card not starting whatever the card model is). On the other hand... the MSI MB is still running fine after 8 years! So you should be happy I guess and Ivy Bridge + PCIe3 support is a big bonus.
My Asus MB and also the Asus graphic card got easy overclocking ("auto" or push button) features too. Never tried so far BTW. I don't experience any lack of processing power so far.
Glad you got a nice system. I hope you'll solve your credit card issue... BTW I'm seriously worried by the increasing number of issues with companies rejecting credit cards and customers based on totally stupid and unfair criteria.