Thanks a lot for the ideas. I put a Prodigy P3 brake controller on today and it's a dream. Looking forward to the trip now. I didn't know about state's having a law about trailer brakes, so thanks for that. I will post once trip is done in June-ish.If you are pulling 3,500lbs that far, you need a brake controller if you use the 2008. Most states legally require at 1,500lbs/2,000lbs.
Another thing that makes towing A LOT easier is if you get a weight distribution hitch. They can be pricey; I got a used one off Craigslist for a great price and it makes towing heavy loads a real breeze in comparison - balancing the vehicle and trailer as well as stabilizing the trailer. It will track directly with the tow vehicle and not sway or push - especially a taller trailer (I used to tow horses frequently). This is what I am talking about: