Everything there should work together. I have never used a Rosewill PSU so I don't know how good quality they are. Personally I would get a more reliable brand like corsair. As what is this rig going to be used for? I ask because the 4670 seems like an odd selection for a GPU compared with the rest of your build.
mostly video editing and very light gaming (nothing serious). I agree but I just cant afford $99 for it "CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply " I have never used a Rosewill before but have not heard any bad reps from them either. What about the "4670" are there any other you suggest ?
In terms of compatibility, it really only concerns the CPU, motherboard and RAM.
Your CPU is AM3, your motherboard is AM3, and your RAM looks fine, so it should all work. As for the PSU, I'd get something more well-known and reliable, i.e. something made by Corsair or SeaSonic. I very much doubt that you'd need 750W, even 400W-500W should be more than sufficient. A Corsair CX400W would do nicely, for example.
It's more than enough for your requirements. I wouldn't say Rosewill is bad, but I'd play it safe and get a PSU from a brand I know I can trust.
I'm assuming you're not doing real or extreme high-level editing, so, really, graphic cards won't help that much in terms of rendering. An HD 4670 is a great card for light gaming.
For $6 less, get the HIS Radeon HD 5670 IceQ 512MB GDDR5 - the extra memory on the HD 4670 won't help much at all, and 512MB is sufficient for light 1080p gaming.
I would personally go with this build. I just based it on a 770 budget so don't know if you want to spend more. Only difference in mine is I add a 5770 which is a better GPU for gaming, different case and psu, and slower memory timing. You can always change out the memory if you want. Total is 769 including shipping and includes a 25 rebate.