If i remember correctly, the offset on 16" is 35mm, not sure if it would be the same on 17" alloys.
As for are they any good? Well, depends which brand you go with.
Ultralite make decent alloys, these come in a 42mm offset so will sit further out than the standard alloys. Ultralite Wheels
My preference would be ROTA wheels, a friend has a very nice set on his scooby. These also come in 48mm offset that would fit the freeby. Rota Formula Mesh - Wheels