Well you want a converter with Antiballoon plates, I don't think the smaller stall Yanks have them. Antiballoon keep the converter from swelling under load...not a good thing. Upper end converters have them.

I'd get a used PI. They sell for about $400 typically. If they are less than 2 years old you can get a free restall to what you want and for $300 more you can get a multi lockup clutch installed also.

PI is my No 1 choice in converters. Yank does well too but they have LOTS of problems in customer service...not what I want in a performance company. PI is just a sweet converter.