I'll echo what coolmom said about the brakes, this is a big deal even for a light weight popup. They can get squirmy on you real fast and the brake are needed for that. Yes the sway bars can help but the brakes are very important since you need to not only pull that much weight but stop it as well and without you are putting a lot more strain on your Caravan brakes which will wear prematurely.
Do you have a 7-pin wiring harness installed on the back of the Caravan? If it did from the factory adding a brake controller usually isn't that tough, if you don't feel comfortable doing it the dealer can. This should include a charge line within the 7-pin harness which will also charge the pop up batter while you are driving. Many popup fridges also work off of 12v while traveling too.
I had a 2001 Coleman Niagara, a heavy beast. I used a simple Friction Sway Bar as I didn't really need much else. This photo is what one looks like from another member.
