Hello and welcome to the Forum.
There is only one real substitute for total Cubic Inches and that is Cubic Dollars!!
Having said that, how much are you looking to spend and how much bang for the buck are you looking for?
CAI is only good for about 5HP in the daily driver RPM ranges and about 10 to 15 additional ponies in extreme driving range. Truth be told, the OEM intake is not overly restrictive when one looks at the real breathing bottle necks such as heads, headers, and exhaust system. The basic function of horsepower is total flow IE throughput. Air flow isn't everything of course, but if one is getting as much air and fuel in the cylinder as possible that will efficiently burn as completely as possible, flow restriction (both in and out of the engine) is controlling the most bang for the buck after the basics are all taken care of.
Now all functions of that have several areas that interface as well as react with each other. Yes if you install a wilder cam and adjust timing, port and polish the head (intake and exhaust), change out the headers, and open up the exhaust, one will get to the point where the stock air intake IS overly restrictive and affecting usable horsepower.
So if you are worried about intake air flow, reinstall the CAI. Then buy a performance chip or buy a chip programmer (don't know which would be better for a 4.6). Then see if that is enough since you have helped the exhaust already. After that I believe you are are looking at engine parts and labor intensive things for any real gains.
If you want it all at one time and don't mind a permanent daily mileage drop, then upgrade to a 5.4L 3V. It is sometime worth it to see if replacing the engine with more cubic inches could end up costing less then what all is needed to gain 30BHP in the 4.6L.
Last but not least, if you want to keep the daily driver the way it is as well as keep the daily mileage, its time to go on the Bottle! Especially if this is just to put away some daddy provided kids SUV. For $1300 to $1500, one can have 75 to 150 extra ponies at the push of a button. These systems are dual fogger per cylinder NOS so there is no fear of 4 lean and 4 rich cylinders as there is with a single plate system. Single plates are fine for carburetors, not good for fuel injection.