ATI's RV730XT comes as a 1GB card and 512MB card. Both cards have GDDR3 memory and they will consume much less than projected 75W. Both cards are full length and there will be a small price penalty if you decide to go after 1GB version.

The 512MB version will launch in early September, probably after 10th while the 1GB version should be available by mid of the month. The card is a full length and it comes with two dual link DVI's and TV out.  

The Radeon HD 4650 will have 60W dissipation, DDR2 and slower clock but it might come with Display Port and HDMI for your amusement.