You've got the right idea as first mods. Don't forget a tune if you go with an aftermarket CAI, most of them require a tune unless specified otherwise. A couple of great places to look at would be
www.bamachips.com and
www.brenspeed.com. They are both great tuners which really wake the 4.6's up.
I don't have them, but a lot of people swear by 4.10 gears. An aluminum driveshaft is a great mod to do although a little pricey. Of course underdrive pullies and charge motion delete plates are smaller mods that don't net quite as big of results as some of the bigger mods, but comparitively speaking, they don't cost near as much ($130 for the plates, 200 or so for the pullies). Both are good for around 7ish horsepower.
Also, if it doesn't have lowering springs on it already, get some and get rid of that 4X4 look! A good place to start looking around at those would be
www.steeda.com. I have their Ultralite springs and love them. They put right at a 1" drop all the way around.
do u have a pic of ur car with the springs on?
By the way, welcome to :SNSign: