The first one is definately overclockable as you can see by the reviews and I am about 80% sure the second one is also. However I would recommend a motherboard from a more trusted brand for overclocking. Try to get a board from Asus or DFI, they are the well known overclocking brands. Im not an intel guru for motherboards so maybe someone else knows a good overclocking mobo in his price range?
I'd stick with an ASUS or other well-known brand if I were you. ASUS makes some great Intel OCing boards as far as I know, although I'm not too knowledgable about Intel boards, so maybe someone else can give better advice.