I wouldn't reccomend to buy stocks if it's only for a period of 1-6 months. You could buy treasury bills of course.
EDIT: If you're going to have one longterm part, it depends on several things, but the safest would be to find a hedge-fund with low risk. It might only have a yield of 3-4%, but it's low risk. If you are willing to accept higher risk, but higher return, there are several stocks to consider.