I used to work for Ford at the Ranger/Mazda B assembly plant and field tested the tremor and edge series. The tremor is basically your run of the mill ranger w/ some decals and an overpriced aftermarket stereo and maybe some other cosmetic additions. I would personally just buy a "stock" ranger and add evrything u want and nothin u don't. I strongly recommend the 4.0 V6, it's got some balls, especially thru the 5-speed. But if you like what the tremor offers, than more power to ya.
The 2004 Ranger is a little different than the 2003. The differences include: the gauge cluster, the steering wheel, the color choices (drop yellow, add 3 others), a more powerful system in the Tremor, Tremor avail. in 4x4, a new (very tacky) grille, and new availability of the same (as 2003) wheels.
Wait till the 04's are beginning to get delivered, and strike a deal on an '03 for about $6k off MSRP. Around ATL, they are already going for that amt. ($6k off)