CTB1

Hi all. Newbie here with my first post - hopefully these things haven't been done to death and I wasn't smart enough to find the threads... Quick background:

* Looking for something to tow 4000 lb of race car/trailer (combined), maybe 8 times a year. Nothing's more reliable than a Toyota - several in the family.
* Done searches, can't find dyno charts for 2003+ 4Runner and 2005 Tacoma V6
* Wouldn't mind seeing the dyno chart for the 2003/4 V8, or the new one coming in January, too.

Does anyone know of dyno information like this? It would be very useful to me.
Also, what does everyone think of the 2003+ 4Runner for towing? I have electric brakes on the trailer, and I'd get the Sport Edition for the larger brakes if I got one. Would you recommend a 2005 Tacoma instead? Is it worth spending the money for the V8 4Runner for this? The V6 looks pretty muscular.
Any opinions or people with experience towing with these would be really great. Thanks!

Edit: Oops, forgot to mention a couple things. I'll be towing through the hills of Pennsylvania at times, and I'd also like to be able to move along at 75 mph with the trailer. (Very possible out here in the flatlands.) Thanks!