Good i7 build? Hard drive suggestions?

Hey everyone, this is my first build so I appreciate any input. This will be mostly a gaming computer where I'm hoping to play most games at decent settings on 1920 x 1200. Eventually I will get a second GPU for crossfire when the 4890 goes down in price.

I also want to eventually get a tuner card and have the computer function as a DVR, which brings me to my next question... How big of a hard drive should I be looking for since I will be recording shows? I also plan on having one partition for Ubuntu, and another partition for Windows 7 so plenty of storage on both would be nice. I've seen alot of 1TB drives selling for pretty good prices but there are a few reviews always mixed in saying the higher capacity drives seem to be less reliable. Is there alot of truth to this?

As of now here is what I have:

CPU
Intel Core i7 920 Nehalem 2.66GHz 4 x 256KB L2 Cache 8MB L3 Cache LGA 1366 130W Quad-Core Processor - Retail

Case
XCLIO Windtunnel Fully Black Finish 1.0 mm SECC Chassis ATX Full Tower Computer Case - Retail

MB
ASUS P6T Deluxe V2 LGA 1366 Intel X58 ATX Intel Motherboard - Retail

RAM
OCZ Platinum 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Low Voltage Desktop Memory Model OCZ3P1600LV6GK - Retail

GPU
SAPPHIRE 100269SR Radeon HD 4890 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

PSU (is 850W plenty for adding crossfire, tuner card, and maybe something else I haven't thought of yet?)
CORSAIR CMPSU-850TX 850W ATX12V 2.2 / EPS12V 2.91 SLI Ready CrossFire Ready Active PFC Power Supply - Retail

Cooler
COOLER MASTER Hyper N 520 RR-920-N520-GP 92mm Sleeve CPU Cooler - Retail

Optical Drive
Sony Optiarc Black 5X BD-ROM 12X DVD-ROM 32X CD-ROM SATA Internal 5X BD-ROM & 12X DVD Burner Model BC-5100S - OEM

Monitor
Acer X233H 23" Widescreen HD LCD Monitor - 1920 x 1080, 40000:1 Dynamic Contrast Resolution, 5ms, HDMI, DVI, VGA, Energy Star, Tilt Mount

Hard Drive
SUGGESTIONS???

Total cost after combo deals and mail rebates
1312.91 + whatever the hard drive costs

Whichever Western Digital hard drive will suffice. Seagate seems to have problems in the higher capacity territories.

850W PSU is a safe number...

If you want to add speed to your system, you can look to add a OCZ Vertex Series OCZSSD2-1VTX30G 2.5" 30GB SATA II MLC Internal Solid state disk (SSD) - Retail for your OS and than have a secondary drive of a Western Digital Caviar Black WD6401AALS 640GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM for everything else. I don't know your budget so this may or may not fit. If not... just get the WD 640 Black HDD.