Oh my... at 2,500 USD budget? No no, we must change many things. The following parts list will destroy what you have listed above. This is just the PC, the additional accessories will be listed below this (including monitor)
Case: Personal thing, the one you selected is more than ok.
PSU:
http://www.newegg.com/Product/Produc...82E16817139007
Although more expensive, it is 80+ certified, has been getting PHENOMENAL reviews, and Corsair's PSU division is putting out some of the most stable PSUs on the market today. Coolmax is not a good company, despite the good reviews Neweggers gave that one.
CPU:
http://www.newegg.com/Product/Produc...82E16819115037
Your choice is good, as the Q9550 can be overclocked very well, and is a great performer. It represents the perfection of Penryn quad cores. HOWEVER, that is just it. Penryn Core2Duo chips are best in dual core form, not quad core. The E8400 is half the price, and most things you will be doing won't use the current architecture of Intel quad cores. Nehalem will change that a bit, but for gaming, a dual core is MORE than enough. Save money here, and you will get a processor that can overclock better, and is already clocked higher. It is a win win situation.
RAM:
http://www.newegg.com/Product/Produc...82E16820231189
GSkill is an absolutely amazing company with some of the best prices. This is some of the new low voltage (1.5v) DDR3 1333 memory, with really tight timings (8-8-8-21) This RAM would be perfect to through into a Nehalem setup down the road.
You only need 4GBs of RAM, 8GB is overkill. Trust me.
HDD:
http://www.newegg.com/Product/Produc...82E16820167005
If you are going Solid State, don't get a piece of crap cheap, slow drive. Intel's SSD drives are unparalleled, and you pay for what you get. This might push you over budget slightly, but if you are really concerned about getting an SSD, get this on. The one you suggested will hang after each command, and that hang will drive you completely INSANE, as it has most reviewers of most SSDs. Intel's do not have that issue.
The final price I list will be with the Western Digital Raptor drive I have below, not this SSD. This is an additional cost if you are positive you want to go with an SSD.
HDD Alternative to SSD:
http://www.newegg.com/Product/Produc...82E16822136296
Get that if you decide not to go with the Intel SSD. It would be the next best choice. The 150GB is plenty for your system drive.
Media HDD: Stick with your choice, the 7200.11 drives from Seagate are the best on the market, period.
Motherboard:
http://www.newegg.com/Product/Produc...82E16813188031
The last generation 790i board from eVGA is the pinnacle of gaming performance. Not only will this board shatter any world record set by any other board, but it will cook dinner for you too (just kidding...

) With 100% SS power layout, vDROOP control, and the true 8 phase PWM, you are sure to splooge yourself with this board. Yes, it is pricey; yes it is worth it.
GPU:
http://www.newegg.com/Product/Produc...82E16814130398
Two of those, to be specific. They give the best performance for the buck. The GTX280 is very expensive, and the GTX260 (revB) is equal to the mighty 1GB HD4870. Two of these in SLi scale very well, and will destroy any game you can throw at them (even Crysis at high [not very] settings)
CPU Cooler: Your choice is excellent, stick with that. Arctic Silver 5 or Ceramique are the best thermal compounds on the market as well, so stick with those.
DVDRW Drive:
So that is the PC. We are at $ not including shipping.
Here are the peripherals to go along with it.
Monitor:
http://www.newegg.com/Product/Produc...82E16824001309
28" is overkill, to be very honest with you. I own a 24" Samsung 245BW, and it is more than large enough. The 28" doesn't have a larger resolution than the 24", so the pictures will simply be less sharp. Samsung also is infinitely better than Hanns-G.
Throwing in the monitor brings us to:
$2,336.88
Mouse:
http://www.newegg.com/Product/Produc...82E16826105223
Personal thing, your choice is fine I guess. A bit expensive though, and lots of people hate the design (I read many reviews) I would honestly go with something a bit cheaper. If it is 2000+dpi, it is perfect for gaming. 4000 is just silly overkill marketing crap. I use the above mouse, and LOVE it. You need big hands to use it though. The G5 from Logitech is great also, as is the MX518.
Keyboard:
http://www.newegg.com/Product/Produc...82E16823109063
The new orange G15 is terrible. Go with the above, you will not be disappointed. You can also go with the Saitek CYBORG keyboard, if you want a different look.
Mousepad:
http://www.target.com/Allsop-Metal-A...Aallsop&page=1
35 dollars for a mouse pad? Seriously? Just no... Find a cheaper solution that is made of metal perhaps? Durability > looks. Razer is taking you to the bank. That is the mousepad I have had for years, and it is as good as the day I bought it. It is precise, smooth, and sleek. ALLSOP is a very overlooked company with a great product. Newegg doesn't carry it, unfortunately.
<font color="red" font size="4">GRAND PRICE (Excluding mouse pad from Target.com) W/ SHIPPING = $2,490.44</font>
<font color="blue" font size="3">As a note, the setup I have for you above will slaughter your original setup, even without overclocking. The setup you originally posted didn't focus on gaming specifically, but more on multimedia and workstation work. If this is to be a gaming setup, I would heavily advise my setup to you.</font>