I know you've already decided what to do, but I just wanted to defend the "taco motor"
If you are boosting an engine, then I agree that you can get more reliable power from more cylinders. But the Tacoma engine is one hell of a great engine. It is dang near impossible to stall out (perfect for wheeling) and still puts out a good 160 Hp / 185 Tq with simple bolt-ons. Give it just a little bit of boost, 6 psi or so, and it'll dish out 212 Hp / 252 Tq according to TRD (Smog Legal). That is 63 Tq per cylinder.
If those 6 cylinder M-engines were as efficient as the 3RZ then you'll be up to 378 Tq!!!!! (63 x 6cyl)
Now if you can make 378 Tq from just 6 psi of boost from the 5M/6M/7M/3VZ/5VZ, then DO IT!! But I know its not possible 
The 3RZ is one hell of an Engine. Period.
I think I understand what your trying to say, but it should be foot pounds per cubic inch or cc. The straight six cylinders are smaller, apples to oranges.
If I could afford to do a 3rz swap, I would. Why stop there, 3.4L v6?
