Thinking about replacing HD DVR, would like some suggestions

I've been reading this forum for a few weeks now and I think I have finally decided the Comcast HD DVR sucks enough to be replaced. I'd like some input on a system I've started to plan before I get too far down the path of buying components. Here is what I want the system to be able to do:

• Primary use is to be DVR for Comcast digital service. I plan on using the Ceton PCIExpress CableCard tuner, but dont know which cable guide I want to use. Possible the one that comes with Windows (it is still available in Win7 x64 Home Premium, right?)
• Secondary use is to play Blu-Ray discs and media files already on my server and other other computers. I have a 2.1 soundbar system that I would like to connect to using an optical connection.
• I'd like to also be able to occasionally play a game on it, so I think discreet graphics are needed. I'm not looking to play with everything turned on, and in fact it would be more for my wife to play some older games most likely, since she now runs a mac.
• This needs to fit inside my entertainment center with limited cool air intake. I'm also planning on running this mainly off of a Harmony One remote. I would prefer it to be as quiet as possible too.

So here are my constraints:

• I'd like to stick to Intel and Nvidia. It's just what I'm comfortable with.
• I'd like a good case that can support all of it but also looks like it belongs in a media center.
• Overall budget cannot exceed $1500 shipped from Newegg (I would consider some other places to shop if they have decent prices for superior gear).

Here is what I was thinking:
CPU: Intel Core i3 2125 Dual Core 65W with integrated HD 3000 Graphics
Mobo: EVGA Z68 SLI Micro 120-SB-E682-KR
GPU: EVGA 01G-P3-1521-KR GeForce GT 520 (Fermi) 1GB 64-bit DDR3 PCI Express 2.0 x16 HDCP Ready Low Profile Ready Video Card
TV Tuner: Ceton InfiniTV 4 Quad-Tuner
Ram: Mushkin Enhanced Silverline 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model 996770
Hard Drive: Western Digital Caviar Black WD2002FAEX 2TB 7200 RPM SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive

After that, I'm having a hard time to decide what is needed. I'm thinking I need to add an aftermarket cooler, soundcard, a decent power supply (in the 500-650W range). So I tentatively add:
Soundcard: Creative Sound Blaster Recon3D Fatal1ty Professional (70SB135600000) 5.1 Channels PCI Express x1 Interface Sound Card
PSU: Antec BP550 Plus 550W Continuous Power ATX12V V2.2 80 PLUS Certified Modular Active PFC Power Supply
CPU cooler: COOLER MASTER GeminII S524 120mm Long Life Sleeve CPU Cooler Compatible with Intel Sandy Bridge (I'll replace the fan that comes with this with a Noctua P-12 or F-12 most likely, I will have spares after I finish my upgrades to my main computer).

Besides that, I was going to add a Blu Ray drive and I was leaning towards the Lian Li PC-C33B case.

With all of that being said, what am I missing? What software should I be thinking about that I havent yet. Is this overkill for my what my requirements are? Is 2TB enough for a decent DVR? Should I spring for faster RAM? Thanks for reading my long post. Any suggestions would be much appreciated.

The main games I think that will be played on this would be some of the older Tomb Raider (like Anniversary, my wife likes it), some Popcap games like Peggle, up to hopefully using it to log into Star Wars:TOR to check mail, maybe Oblivion as well. Thanks for the suggestions, I'll stick with the stock cooler and look for a different mobo. I was thinking about just buying a Rosewill Windows Media remote and substituting the Harmony afterwards using the usb ir receiver. I'll look at the Silverstone case.

One thing about the sound card, is onboard good enough for Blu Ray playback?

Thanks again!

Yes I have a receiver. Its a 2.1 soundbar system that has 3 hdmi in 1 hdmi out. Would I notice a difference with the soundcard?

Thanks for all the help guys. I've decided to change to most of your suggestions. Here's the new build:

Case: Silverstone GD05B
CPU: Core i3 2100
Mobo: Intel BOXDP67DEB3 LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard
Cable: Ceton InfiniTV Quad Tuner
GPU: GeForce GT 520
PSU: Antec BP550 Plus 550W Modular Power Supply
Boot Drive: Intel 520 Series Cherryville 60Gb
Storage Drive: Western Digital Caviar Green 2TB 6Gb/s
Ram: Mushkin DDR3 1333 2x4GB
Blu Ray Drive: LG Black 12X Internal Blu-ray Drive 3D Playback & M-DISC Support SATA Model UH12LS29 LightScribe Support - OEM
OS: Win 7 x64 Home Premium

And I'm going to throw in a Rosewill Win 7 Infrared Media remote to ensure I have the IR receiver. I'm right at my budget, but significantly lower after your suggestions. Thank you! Now I have to see about getting a CableCard before my wife lets me place the order.