Photo editing PC

Please critique the system I am planning (noob):

APPROXIMATE PURCHASE DATE: This week. BUDGET RANGE: $1200 After Rebates

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Photoshop CS4 editing of 18 mp raw files; CD ripping and transcoding; Web; office apps; serving up music files to Squeezeboxes around the house. I tend to multitask. No gaming.

PARTS NOT REQUIRED: one hard drive, keyboard, mouse, monitor

PREFERRED WEBSITE(S) FOR PARTS: newegg.com, COUNTRY OF ORIGIN: USA

PARTS PREFERENCES: None.

OVERCLOCKING: Would like to try (no prior experience). SLI OR CROSSFIRE: Not planned.

MONITOR RESOLUTION: up to 2560 x 1600. Dual monitor capability desired.

ADDITIONAL COMMENTS: Case must be less than 18" tall.

Intel Core i7-860 Lynnfield 2.8GHz 8MB L3 Cache LGA 1156 95W Quad-Core Processor
GIGABYTE GA-P55A-UD4P LGA 1156
G.SKILL ECO Series 8GB (4 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory Model F3-10666CL7D-4GBECO
GIGABYTE GV-R467ZL-1GI Radeon HD 4670 1GB 128-bit DDR3 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card
OCZ Vertex Series OCZSSD2-1VTX30GXXX 2.5" 30GB SATA II MLC Internal Solid State Drive (SSD) (OS and key programs)
SAMSUNG Spinpoint F1 HD103UJ 1TB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
SAMSUNG Black 22X DVD+R 8X DVD+RW 16X DVD-ROM 48X CD-ROM 2MB Cache SATA CD/DVD Burner - OEM
Antec EarthWatts EA650 650W Continuous Power ATX12V Ver.2.2 / EPS12V version 2.91 Power Supply
NZXT GAMMA Classic Series GAMA-001BK Black Steel ATX Mid Tower Computer Case
Arctic Silver 5 Thermal Compound - OEM
Windows 7 Professional

System cost as above ~$1180 (before tax)

I plan to transfer an existing SATA hard drive from current PC for a total of 3 drives (SSD plus two rotating platter drives)

Do I need a third party CPU cooler?

Will that RAM work (it is 1.35V)?

Is 8 gig ram overkill for my intended usage?

TIA.

Mike

Could I go with a mini-ATX Mobo and case, get everything to fit, and achieve enough cooling to do a mild to moderate overclock?