I have a 2012 176 and have been towing it with a 2004 Toyota 4-Runner, the model with the V-8. I always use a sway bar after earlier towing experiences with other trailers and almost having my SUV whipped off a mountain road. Also, Washington highways get grooved from the studded tires and the wider spread of the RPod wheels causes the trailer to 'search' back and forth. The sway bar works wonders.
I have a weight distribution hitch, but to be honest, I can't always tell a difference when I use the bars and when I don't. I usually use the bars, but just because I think they are taking strain off the rear of the 4Runner. BTW, I only have one propane tank and one battery on my trailer.
So, in my opinion, the sway bar is a must, the weight distribution bars, not sure.
Enjoy your 176. We really do. We removed the stiff back pads around the dinette seating and just use bolsters and pillows. Much more comfortable and flexible.