Gears are really a combination of opinion and what are you trying to get out of your car. Do a search on here, there are a ton of threads about gears. There are many good discussions that talk about what gears to put in to get what you want out of your car.
I don't have any FI yet... But I do have 3.90's and I love them. IMO 4.10's would have been to much. I drive mine every day in town and on the highway.
If your making it a track car, or a weekend fun car then 4.10's might suite you better. Do your research before you pull the pin on gears man.