Ram and MotherBoards

Hello Forum, I bought 2 sticks of Kingston  2GB DDR2 800MHz CL6 ram and on the new motherboard I will be getting, it has 4 slots of available ram. I don't really want to buy another set of 2gb ram sticks because I want over 10gbs, and if I buy 2 more sticks I would only have 8gbs. I was wondering if I could use the 2 sticks I already have, and then buy 2 G.Skill Ripjaws x Series (2x4gb) DDR3 1600mhz CL9 Ram. If I were to add all 4 of those sticks (the two I already have, and the two I want to add) of ram into my new motherbaord, would my computer be able to use all of it? Or would I have to get 4 sticks of ram that are exactly the same?

No, those are two different types of RAM; you can't fit DDR2 and DDR3 on the same board.