What transmission??

[slow92]

I know that sr20 transmissions are super weak and everybody talks about it but no one ever says what transmission is the best to use to upgrade with. I know about the vg transmission swap but it is still a 5 speed and I would really like to go with a 6 speed manual but one that isn't weak like the s15 tranny. I was curious if anyone knows about an adapter kit for using the 350z trans or even using a mustang t5 transmission (I know it isn't a 6 speed). I am going to do a rebuild in a few months and am just trying to get some advice so I can do everything while the whole longlblock is out of the car.