1 advertise here, ebay, local paper, with how much you want
2 tell them the reason you are moving, how long contracts are for etc,
3 get solicitors involved to draw up a contract of sale, to protect both of you, listing what is included and not included in the sale etc, any one who is genuine, should not have a problem with this, u might have to work with them for a month ie 2 weeks you make the money 2 weeks he makes the money, to show him the ropes this will look better on you, rather than some one who takes the money and runs
is ur company ltd?