If you are going to buy one. Call a Converter builder and pick their brain on what is best. It is only a phone call away and its FREE. Have all your information about your car when you call and be HONEST.
Give the builder all of the specs you have listed, approximate weight and intended usage. If you intend to play once in a while probably somewhere around 3200, BUT it would be best to have one built specifically for your combo. A little pricey, but doing it right the first time is the best scenario.