Stock ring gear is 7.5", I recommend going to 4.10s if you are changing them. You will also need a T-Lok or other limited slip differential. Since you have a relatively new 04 model I would go with new parts.
4.10's are cool, I have them and love them. It really depends on what you are going to be useing your car for. Everyday driving with some slight modds and the occasional blast down the strip, then go with 3.73. Everyday driving with mild to heavy modds and/or a poweradder going to the track once every two weeks, then go with 4.10.
4.10's on a mildly to heavy modded car would get you into trouble as the ratio is so steep you would break the tires loose everytime. 3.73's are good for a lightly modded car/ YOu might even want to consider 3.55's instead which would be about the middle of the road.
On my 98 manumatic, the 4.10's constantly cause the rear tires to break loose from 1-2 gear, and sometimes 2-3 gear, and that's with only ram air, axhaust, and shift kit.
410s on a power added V6 is a terrible idea. 373s in that case. I have 4.10s for a daily driver, highway and city. I love them. It makes the car get up and go. I also have an 8.8 rear end though.