If it's performance gains you are looking for, don't waste your money. You won't get much with any of them. You should consider Gibson also. IMO, the Gibson has a different sound than the others (no rice) but that's your call.
I just finished installing the Borla cat back on my 01 SC with URD fuel mods 3.4 4x4 and I love the sound. I went from a flowmaster 40 series with all stock piping to the Borla setup. The flowmaster was a little loud for my taste. The borla still lets you know its there but not nearly as loud in the cab, but when you stomp on it on the highway it really sounds good. I can't really comment on the fuel economy yet but I can say that it does feel like I may have a little more power now feels like the truck can exhale a little better now. BTW..the best price I found for the Borla system is through JC Whitney for $429.99 but be prepared to wait at least a couple weeks to receive it..possibly a month. And when I received it, the first section of pipe that bolts to the cat converter would not mate up...Borla didn't weld the flange to the pipe evenly but a dremel with grinding attachment fixed that problem, I just smoothed out the inside of borla's pipe to make it a smooth fit over the piece of pipe that sticks out from the cat converter.
If Borla makes an application for your truck, I'd get Borla over the TRD. In fact, the TRD exhaust uses a Borla muffler, not sure whether the rest of the system is made by Borla or TRD. Also, the Borla system is a side exit like stock and the TRD exits the rear which IMO doesn't look good on a prerunner or 4x4. Unfortunately, Borla does not make a cat-back system for a DCab which is what I have. As bb609 mentioned, look into Gibson exhausts too. Luckily someone makes a DCab cat-back system which is Gibson. They're cheaper than the Borla and TRD systems and offer them in two styles, aluminized piping or stainless steel. I'd opt for stainless steel if you plan on keeping the truck for a long time. The aluminized systems go for under $300.
I just had a 20" Dynamax installed today. I have headers and a s/c. The sound is just right. Not too loud, but louder than stock. For a V6, I'd definitely stick with a longer muffler. Before the install, I was going to have them add a resonator. Didn't need it afterall.