The 5.0 is nice but the MT-82 manual trans is looking like it's going to be a nightmare if you beat on it any. I'd be happy with the 6-speed auto and a looser converter and of course some boost .
I don't think it's that the tranny is weak,there is a bunch of the manual trans cars going low 10's with the stock tranny,run after run,i think there is even a 9 second manual trans car on you tube.
It seems that the manual trans that are messing up are because for some odd reason they just wont shift,and/or are grinding going into gear,but alot of them are people that only have a few hundred miles and have never even spun the tires or beat on them (so they say)because they arn't even broken in yet.
I think it may seem like there is more problems then there really is with them,because everyone with that shifting problem ends up in the same place,they google it + find the same thread or 2 about the problem + chime in, I think if they get that shifting thing sorted out on those with the problem, the manual trans should be fine,It's actually pretty amazing how well the stock trans without the shifting problems are handling the power of a low 10 second car.
But I'd go with the auto anyway, especially if i was going to supercharge it + go 10's.
A couple of 10 second manual trans cars,launching hard on slicks.