I went to home depo and bought a chain that was long enough and strong enough for the purpose that I needed.
When you go to home depo they have all different grades/sizes of chains so just use your common sense as to how strong a chain you will need to pull a 30 lbs weight.
They will also have the necessary attachments for only about 1.50 each ( I don’t know what they are called. C clamps?) where you can attach the chain to the tire and to your belt.
As far as the tire just punch a whole in the middle of the tire and fabricate a connection from the tire to your chain.