Hi Bill,
Are you asking which EXHAUST brake is the best?
I don't think you're going to get a clear consensus here... everyone will have their own opinion. All of the exhaust brakes on the market work pretty well and you'll just have to balance price, features, and brand reputation. I'm partial to the Banks exhast brake because that's what I have. I like the fact that it doesn't require an extra compressor on vacuum pump to operate. It uses the engine's existing vacuum system.
Whatever brand you choose, with an automatic transmission you MUST install some type of device that locks the transmission torque convertor when the exhaust brake is engaged or you'll have minimal braking force getting to the wheels. Most manufacturers offer such a device as an option. For Banks it's called a "SmartLock. "
Best regards,
John L.