8800GT uses around the same amount of power, but gives you MUCH better performance, and only costs around $30 more. Only thing the 4670 has is a shorter PCB Form Factor. But as long as your case can support longer video cards, the 512mb 8800gt is better in every aspect. Also nvidia drivers are stil...

you are already close i guess (would invest in more ram though vista eats it and will page to disk a lot on 1gb) any 7 or 8 series card is capable to do 720p even the cheapest and that includes h264 decoding (al but the cheapest of the new ati line will do 1080p ) the 7600gs wil play most games with...