Ram 3500 vs 4500

It can be insured with regular auto coverage and driven as a personal vehicle if you want to buy the truck first and then work on getting set up to run it. Or I suppose you could try to set up a DOT/MC with no truck but the insurance policy will probably want to know what kind of truck it is/VIN # etc to give you an accurate rate. You'd have to call around and ask about that approach because I've never done it.

I suppose the other option if you were dead set on starting out with a bigger truck would be to buy it and park it somewhere until the insurance and paperwork was set up. That's a big part of the reason why driveaway companies like truckmovers exist. They have the red tape taken care of to drive or transport them under their own insurance and authority. But generally it would be a bad idea to buy anything until you got some quotes for the insurance policy. It's a little bit of a catch-22 in that you need the truck and insurance but getting one without the other isn't easy. The 3500's are easier to get going with since they are the largest truck you can buy and drive home with a standard auto liability policy. There are loopholes for larger trucks that are RVs but that doesn't work with for-hire commercial vehicles.