tow dolly

I used a Roadmaster for about 10 years. Then got a veh. to tow 4 down due to health. What you are going to need is brakes on the dolly if it and the toad exceeds the weight that your state allows without brakes. You should also get a wiring harness allowing you to light both tail and brake lights in the toad as your toad's rear end is probably more than 3' behind the dolly tail lights. I highly recommend getting brakes on whatever dolly you get because you will be adding in the neighborhood of 3,000 lbs. to your rig and every little bit of braking power is worthwhile. I didn't have a problem towing my 2000 Honda Civic, but hooking up and storing in a campground could be a pain. I also recommend putting a jack stand with a wheel on the front of the dolly tounge so you can move it manually. Gets very heavy trying to lift and move. I also installed a hitch on my Honda so I could move the dolly with it. Sometimes a very small grade will defeat your ability to manually move that dolly.
The reason I recommend a connection to your toad's brake and tail lights is that if you get an umbilical with it's own lights (generally magnetic) you will find that cable will take paint off no matter how tight you think it is. It will move on the paint. Mine did no matter how I tried to keep it still. My comment about brakes is to get a controller for the MH, utilizing the brakes on the dolly. You don't have to get an aux. braking system for the toad.
Hope it helps.