Great site with lots of useful information. I currently run a Win 7 with the below spec machine and find its a bit slow in Lightroom and when trying to play with GoPro HD footage, so I end up giving up. It's set-up as a HTPC also so I want it to be as quiet as possible. My dad has had macs for a while and I have an old MacBook Pro so was thinking of building a HackingTosh and seeing how I get on with it but will also have the opportunity to dual boot and just use Windows.

Current set-up

AMD Phenom 9850 black edition 2.5 GHz
Zalman ZM600-HP PSU
AMD Radeon HD 6450 1GB (fanless)
60GB Crucial SSD
2 X 1TB Weston Digital Caviar Green 5400 SATA II on Raid 1
SilverStone GD01MX case
Zalman quiet CPU cooler
LG Blu Ray HL-DT-ST BD-RE GGW-H20L SATA connection

so after reading about I was thinking of getting the below motherboard, processor and memory.

Gigabyte Z77X UP5 TH
Intel core i7 3770k
32GB Corsair DDR3 1600

I will be connecting up to a Pioneer plasma via HDMI.

Now since I want to keep this as silent as possible firstly will an additional graphics card assistant in speeding up the video editing noticeable and if so are there any good fanless ones, or any very quiet ones. I was thinking of the EVGA GTX 660 SuperCharged but not sure how noisy this would be.

I guess the first main question after the graphics card is do you think I will see a significant performance upgrade over my old set-up?

Other questions
•Can I get a 6 core i7 processor and if so what motherboard, I quite like the idea of Thunderbolt
•Can I go for any ram faster than 1600?
•Will my existing PSU be sufficient or should I look at a 650W, if so any suggestions of very quiet ones as my current ZM-600 seems to be the loudest component at the moment.
•What would be the best CPU cooler? I have seen a couple of fanless ones on quietpc.com but not sure if they will fit in my case. I guess as long as they are as quiet as the PSU then a fan does not make much difference.
•I was thinking of having two 128GB SSD drives, one for Win and one for OSX but what drives and set-up should I have for storing the HD content etc. the case will fit 6 drives. I guess I can only have 3 additional drives in a raid array as one SATA will need to be used for the Blu Ray drive

I know I have asked a lot but any suggestions/help to getting to what I need would be greatly appreciated.