I use the resin ramps for my cars. I don't know what brand they are and they are only rated 10k lbs. I bought them at autozone so I assume they are chinese. They have a lip in the front to keep from driving off of them. I just use the parking brake rather the chocks that they also sell. They are great for oil changes. I had metal ones that I got rid of for two reasons. First they had a steeper incline so the front bumper trim would hit them. Second, the metal ones often slid on the garage floor as I drove up. The resin ramps stay put.
You can buy heavy duty truck ramps for $1k-$3k if you want something surdier but they would be much more difficult to move arround. Ultimately you need to decide what you are comfortable with.
I'm curious now. I parked one of my tractors on the 10k ramps for the night. If something happens, I'll let you know. The calculated total weight of the tractor with loaded tires, loader and backhoe is ~6k lbs.