You haven't provided all the details of your foyer, so just note that with this fixture, if you can look down into your foyer from the second floor, you're likely going to be looking at the bare light bulbs in this fixture because this fixture allows some of the light to reflect up as well as down.

This drawing is rough because I'm guessing on heights and details in your foyer. Here is a link that might help you select and hang the fixture.

You might want to also refer to a previous conversation on this forum about this subject: http://ths.gardenweb.com/forums/load/decor/msg0414360713685.html

Here is a link that might be useful: How to size chandelier for foyer