So are you planning on overclocking it? (you picked a K series processor) That seems like a risky choice for a computer you are giving away.
700w is a waste - even if its cheap. If this isn't a gaming computer you need around 400w or less. What is more important here in a PC that will run for 7 years is quality. (IMO - Seasonic makes some of the best PSUs, Corsair, Antec, Enermax, XFX, PC Power and cooling are good too. OCZ is alright)