PC build work?

OK, I've been a gamer for some time and decided it was time for an upgrade. I've been trolling through these forums for a few days now and found much usefull information as well as a very informative community. I decided it was best to ask for advice before I purchase my new build because quite frankly I havn't kept up with whats been going on in the PC technology for years now. Anyway, I'll get straight into it and I apologize for the extremely long post ahead.

MotherBoard: BIOSTAR TFORCE TA790GX 128M AM3/AM2+/AM2 AMD 790GX HDMI ATX AMD Motherboard http://www.newegg.com/Product/Prod [...] 6813138130

I chose this motherboard simply for the fact that it supports everything I need it to while not cutting a hole in my pocket.

Vid Card (Crossfire): SAPPHIRE 100259-1GL Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire
http://www.newegg.com/Product/Prod [...] 6814102801

After much research, running this in CF seemed like the best bang for the buck.

Ram (8GB): G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model F2
http://www.newegg.com/Product/Prod [...] 6820231166

I'm not sure if I need 8GB but the price was so cheap I didn't see a reason not to get that much. I don't know much about DDR3 either...except that its expensive. The 1066 from what I read is much faster than the DDR2 800 I have now.

CPU: AMD Phenom II X4 940 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM2+ 125W Quad-Core
http://www.newegg.com/Product/Prod [...] 6819103471

Great reviews. Even though I often run 3-4 programs at once, I thought I might as well get the Quad now since eventually I'll probably need it anyway. And again, price was nice!

P/S: Antec TruePower New TP-750 750W Continuous Power ATX12V V2.3 / EPS12V V2.91 SLI Certified CrossFire Ready
http://www.newegg.com/Product/Prod [...] 6817371025

This is where my faith starts to waver. I don't know much about power requirements. Is this enough for the current build?

Case: Antec Twelve Hundred Black Steel ATX Full Tower Computer Case
http://www.newegg.com/Product/Prod [...] 6811129043

I went with an expensive case for cooling as I don't know much about water cooling...I don't plan on overclocking (if at all, very little). Plus I was told long ago that if you are going to build your own machine, always get a full tower.

OS: Microsoft Windows Vista Home Premium SP1 64-bit for System Builders
http://www.newegg.com/Product/Prod [...] 6832116488

As much problems as Vista has caused me in the past, it is my understanding that to get the most out of my machine (Mostly the 8GB ram) I need a 64-bit OS...plus it said system builders in the name.

CD Drive: SONY Black 18X DVD-ROM 48X CD-ROM SATA DVD-ROM
http://www.newegg.com/Product/Prod [...] 6827118031

I have a dvd burner now...but I've never actually burnt anything so seemed pointless to pay an extra $20-30 for burning capabilities.

Hard Drive: Western Digital Caviar Blue WD6400AAKS 640GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive
http://www.newegg.com/Product/Prod [...] 6822136218

I was originally going to go with a 10000RPM, but I learned on this website that it doesn't really affect gaming much at all.

NOTE: I use a 32" HD TV as my monitor. Overkill I know...and it probably can't be good for my eyes sitting 3ft away from it playing games for hours a day!

So, I know from what I've read that this is a pretty good machine, but as far as compatibility, power requirements, and cooling I'm afraid I might be missing some important things.