Final Check Before First Purchase

I already got a ton of help from you guys in my first thread, and it looks like today is the day to make my first purchase of a computer from scratch and I just wanted to see if you guys have any final thoughts. Also, I unfortunately am shipping this in NJ which means ~$90 in taxes (+~50 shipping) if I purchase from newegg, is there any other one-stop place I could turn to? I'm currently at college and I'm getting the parts shipped to a friend's house so I don't really want to order from multiple vendors and have things arrive at different times though. Thanks in advance.

The list! Prices are pre-rebates.

Case
Antec Nine Hundred Black Steel ATX Mid Tower Computer Case - Retail: $109.99
http://www.newegg.com/Product/Prod [...] 6811129021

I was contemplating a coolmaster, but from what I hear this is better at keeping the computer cold (and is much better looking honestly).

CPU
Intel Core 2 Quad Q6600 Kentsfield 2.4GHz 2 x 4MB L2 Cache LGA 775 Quad-Core Processor - OEM: $179.99
http://www.newegg.com/Product/Prod [...] 6819115018

MOBO
ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard - Retail: $139.99
http://www.newegg.com/Product/Prod [...] 6813131299

Ram
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory: $74.99
http://www.newegg.com/Product/Prod [...] 6820231192

OR

mushkin 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory: $76.99
http://www.newegg.com/Product/Prod [...] 6820146731

My friend uses G.SKILL and it has never let him down but mushkin was suggested in my last thread. I honestly have no idea.

GPU
SAPPHIRE 100245L Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported: $159.99
http://www.newegg.com/Product/Prod [...] 6814102770

If I end up managing to save money somewhere (the ~$150 in taxes and shipping maybe) would it maybe be worth it to move up to the 4870? If so which brand do you think?

PSU
OCZ GameXStream OCZ600GXSSLI 600W ATX12V SLI Certified CrossFire Ready Active PFC: $99.99
http://www.newegg.com/Product/Prod [...] 6817341001

HDD
Western Digital Caviar SE16 WD6400AAKS 640GB 7200 RPM 16MB Cache SATA 3.0Gb/s: $79.99
http://www.newegg.com/Product/Prod [...] 6822136218

Monitor
SAMSUNG 2253BW Black 22" 2ms(GTG) DVI Widescreen LCD Monitor with HDCP Support 300 cd/m2 DC 8000:1: $269.99
http://www.newegg.com/Product/Prod [...] 6824001268

DVD/CD
Pioneer Black 20X DVD+R 8X DVD+RW 12X: $29.99
http://www.newegg.com/Product/Prod [...] 6827129032

Heatsink
ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler - Retail: $19.99
http://www.newegg.com/Product/Prod [...] 6835186134

OR

ZEROtherm ZEN FZ120 120mm CPU Cooler - Retail: $39.99
http://www.newegg.com/Product/Prod [...] 6835887016

OR

Tuniq Tower 120 Universal CPU Cooler 120mm Cooling Fan and Fan Controller/Heatsink: $49.99
http://www.newegg.com/Product/Prod [...] 6835154001

This seems more a question of what price point to purchase. I once again have no clue . I'm under the impression the case already provides a decent amount of cooling and OCing wise I might do some but I'm not going to go crazy with it.

Cooling Compound
Arctic Silver Ceramique Thermal Compound: $5.99
http://www.newegg.com/Product/Prod [...] 6835100009

OS
Microsoft Windows Vista Home Premium SP1 64-bit English for System Builders 1pk DSP OEI DVD: $99.99
http://www.newegg.com/Product/Prod [...] 6832116488

Keyboard
Logitech Media Black 103 Normal Keys 12 Function Keys PS/2 Wired Standard Keyboard: $14.99
http://www.newegg.com/Product/Prod [...] 6823126021

Just a basic keyboard. Wireless would be nice but I don't want to deal with changing AA batteries on another peripheral.

Speakers
Logitech S-220 17 Watts 2.1 Multimedia Speaker System
http://www.newegg.com/Product/Prod [...] 6836121014

Seems like the best base-line speakers. Frankly I usually have my headphones plugged in anyway.

Go with the Mushkin RAM. It will operate at its advertised timings on the JEDEC standard 1.8V. The G.Skill probably drops back to 6-6-6-18 (or worse) on 1.8V.