Which would be best to haul a vehicle with?

I am relocating about 2500 miles from where I curently live. I own a 98 Jeep Grand Cherokee and would like to pull my 99 Chevy Lumina up there. Would it be better to get a full trailor or just a car dolly? The car is in bad shape, needs a complete engine overhaul before it will run good again, so I don't want to also ruin my Jeep on the drive. Also, there might be some downhill driving being I live at 7,000 elevation and will moving to a location of about 1,000 elevation. I would prefer to just sell the vehicle and not take it with but my husband insists because it have been a very dependable vehicle up until about a month ago...so any advice that would save on the wear and tear of my Jeep would be appreciated!