The choice for the 12 sounds good, but keep in mind if one is going to high speed the engine at all (rpm's above 2200-2400) the 12 will not flow the air necessary and the truck will seem to run out of breathe at high speeds. Low end torque will be good, but the trade off is on the high end. If a truck had 3. 08 gears and a 5 speed, then the 12 may be the correct choice, but with 3. 54 or 4. 10's the 12 would not flow enough air to have any kick in the pants on the high end witout getting hot.
I do agree if their were a 14 cm nonwastegated housing it (do to $$$$ reasons) would be the logical choice.
I cannot say their is one correct choice to be made, the choice depends on how ones truck is setup (gearing, other engine mods, etc. ). I do feel for the majority that the 14 will make your truck perform like you expect.
thanks
Don Peters