There are a few people that have welded some things together, but they all have really short runners and they look half baked to me. I wouldn't put them on my car. The longer runners help with intake velocity and down low power where we are lacking. Those short runners aren't doing us any favors.
Plus the intake manifold is actually a really good flowing piece as is, although ugly as sin.
The high rise design is the reason the V6 powerband acts like it does, its kind of a Boss-Esque type of manifold. If you go to a manifold that will improve torque, which BTW would need substantially longer runners, it would hinder top end performance. The design of the Factory v6 manifold is actually pretty good, i've seen some more heavily modded ones hold a flat powerband out past 7200, which is pretty damn good.