The board requires a standard ATX-12V power supply. The necessary wattage can be determined using a Power Supply Calculator. There are all sorts of these on the Internet; I suggest that you use one developed by a power supply vendor. For example, Seasonic offers one here: https://seasonic.com/wattage-calculator.
By the way, you can find all of the documents relevant to this motherboard here: https://www.intel.com/content/www/us/en/support/articles/000022051/boards-and-kits/desktop-boards.ht....
As for an add-in graphics card, you should do an Internet search with a string like "2006 video cards" or "2007 video cards". Actually purchasing any of these cards may be problematic (we are talking 14 years ago). As I look at NewEgg's offerings, the GT 710 seems to be the oldest they carry (but they have lots of different offerings of this for less that US$50), but I don't know if these cards will actually work with a board this old. You may have to resort to purchasing used via eBay or similar...
Hope this helps,
...S
