what is a good stall converter

Take the time, effort and $, call someone like PTI, Turbo, Lupos, etc. Be prepared to give every detail of your car and what you intend to do with it.
They will build you one correctly for your application. Maybe you dont need a fancy one. Initial cost may seem high to you but its cheaper in the long run than buying an off the shelf $200 unit and not being happy. I have a 9 1/2 Dynamics close to whats described in the previous post, it is excellent at the 1/4 and is also at home on the street.