How do you choose who to build your converters?

I'm planning on changing the converter behind the 434 small block in my Dart over the winter and talked to four compaines today, Edge Racing, Abruzzi, BTE and Coan. They recommended 9.5" 10" and the last two recommended 8". I gave them my dyno information and particulars on the car. Coan asked way more questions and asked for dyno sheets, data logs and video of the tach during a run if I had any.

My head is about explode! I'm thinking I'll put all four company names on pieces of paper and drawing one out of a hat. lol