I guess you missed these DDR2 boards:http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010200022%201070947010&name=AM3%2fAM2%2b%2fAM2
HOWEVER: if you plan on a new build of any type or brand I would caution that attempting to "save" your old ram now could end up causing regret in the future.
EDIT: BTW: The gigabyte website shows that with the newest bios your board supports many AM3 chips. Just not the 125W/140W 955 or 965 chips. (It looks like any 95W or less is okay.) You just have to look at the Gigabyte website.