Rusty, I needed a car trailer about 8 months ago to haul around my 1950 GMC 12' stakebed (the Hidden Valley Ranch truck). I've found that you are going to want to go with 5000 pound tandem axles. This gives you a weight rating of 10,000 pounds. The higher weight rating make the trailer more stable. The "off the rack" flatbed trailers tend to be a little cheap. My advice is to go to a custom trailer builder, so they can look at your application and give you the proper trailer. I looked around to buy a trailer but I ended up building my own trailer. I went without the dovetail for better clearance, just built longer ramps. Realize on a 18' trailer a 300 would stick out over the back two feet. I built my trailer 19', max length without getting too heavy. Diamond plate steel bed, better strength per weight. I rented a cheap trailer before and had a harrowing drive from L.A. to Seattle. White knuckles the whole way. I will never do that again. Never forget you get what you pay for. It's not easy to replace a 300. Good Luck, Sean