There are lot of options for a good converter out there. I use Atlantic Coast Converters. They've always done good for me. They used to run a couple of NHRA SS cars.

Just to comment on the JD HyGard fluid. I've been told by a couple of reputable trans and converter builders NOT to run that stuff. They both said if you need to run the thick fluid, then the converter isn't right and needs to be adjusted. They don't like the lubricating properties of that fluid in a high rpm application.