[blue00gt]

1) As was said earlier, internet sites are a great resource. Contrary to what you said, MM&FF has a good amount of stuff on 4.6's every month.
2) Yes, the mod motors can respond very well to bolt-ons. Unfortunately with a '96 the heads are very restrictive and you will not see great gains without doing a swap to the newer style. Most folks suggest gears, shifter, pulleys, and x- or h-pipe as first mods. Cold air kits and throttle bodies are generally a waste of money, but most other bolt-ons yield respectable gains (MAF, timing adjuster). Long-tube headers offer a lot more gain than shorties.
4) The 99+ 4.6 2V has PI heads, camshafts, and intake. Several companies offer complete swap kits to upgrade your motor.