You will hear a few names that are good and most of them will be right.
Converter technology has improved to the point where a 4000 stall converter is perfectly streetable.
The loss of efficiency is no where near what it was when the hot tip was a Vega converter.
10 % slip in high gear is the standard.
I used Lenny at Ultimate and we came up with a 9 1/2 " that should stall in the mid 4000's for my deal. A street / strip small block car.
PTC and Dynamic are both reputable.
The thing to remember is that a 300.00 converter is not the answer.
Expect to spend upwards of 600.00 for quality.
But it is well worth it compared to a bargain converter.