As a brand new AS Bambi 19' owner myself, I too was really worried about towing something so much heavier/longer than my previous trailer (16' T@B). I have the Equal-I-Zer hitch and Prodigy controller and have been very pleased with both. Pulling out from the dealer, I was squealling the brakes and the tech came over and adjusted them for my heavy foot.
The brakes worked great going up Hwy 101 and Intersate 5/80. The hitch, once you've done it a couple of times is a cinch to use. Towing the Bambi was a real joy. It handles well and is very responsive.
Enjoy your decision - whatever it end up. Hope this helps.