4 watts is what you are limited to on the CB, Scott. going beyond that is pretty much useless anyway, as people will be able to hear you, but you won't hear them. VHF is a much better way to "reach out and touch someone".
Being limited to 4 watts really levels the playing field with CB radios. There isn't much heat generated, and they are all pretty reliable. If you stick with the major name brands, you really are just choosing which options you want (sideband, PA output, other bells and whistles).
Besides, you already know that it is all about antenna location, tuning, and length. The 1/4 wave antenna's are hard to beat, particularly with difficult ground planes (like on a jeep). This is what I use on my jeep. Since I have so much "jeep" next to my antenna (as opposed to below the antenna), getting the SWR under 2.5 was difficult with shorter antennas. With the 1/4 wave, I hang out about 1.1. (1.0 is as good as it gets...anything over 3.0 and you are inviting trouble for your radio). In case you didn't know, 95% of the antennas out there have the same 108" of wire in them, regardless of how tall the antenna is. On the shorter antenna's, the wire is simply wound around a fiberglass rod, or inside of a plastic housing.
The ground plane is the first thing to look at. The main mass of metal in your vehicle is the ground plane, for all intents and purposes. You want your antenna centered above this plane, with as little else up there as possible. If this is not possible, you want the antenna as high as you can get it, and definately at least 1/3 of it should be above the highest point of the vehicle. You can get away with having it lower if you move it farther away from obstructions (large masses of metal)....like Chris has done by moving it away from the cab of his truck towards the front bumper. But by not keeping the ground plane centered under the antenna, Chris gives up some performance. In the typical trail setting, you will never notice, but if you were talking to someone who is just on the edge of being out of range, you can see a difference. For your tacoma, I would put the antenna right square in the middle of the roof.
Next look at antenna types. Basically, pick whatever fits your application. I used a 108" (1/4 wavelength) stainless whip. This works great on the jeep because of the lack of anywhere to mount the antenna. I had a hard time getting the SWR down with the shorter antenna's. But, since you have a great place to mount one...I would use a magnetic base...something like a Wilson 500 or Wilson 1000. Very strong mount, removable, reliable, and not very expensive (at least the last time I bought one it wasn't). Oh yea, the Wilson 500 is black with a stainless whip....so no worries about chrome.
Last, look at tuning. Shoot for a SWR of less than 1.2. Not hard to achieve in a application like yours. Just remember, check the SWR on channel 1 and channel 40. If the SWR is lower on 1 than 40, your antenna is too long, if 40 is lower than 1, it is too short. (I always rembember "low, low, long", as in: lower SWR on the lower channel means the antenna is too long).
One final thing....be sure to give it clean power and a solid ground. Ground the chassis too.
