They have a couple on that link that look like a converted baby trike that runners use that would be my choice as it looks the lightest. I used to have one that was a converted hand truck that I but bigger wheels on.
If you want something good and cheap. Go to the thrift store and buy a golf bag cart they have large wide wheels for soft ground and they are light weight. Rig it to your liking.
Just an update... today (yes it’s Sunday!) I received my gun tote. I am totally happy w the product that Richard Otten made me. Very sturdy and my Daystate Regal sits in it like a glove. It’s ALL aluminum and these days aluminum costs a bit. Yea, I could of spent $50 on a piece of poop plastic rifle cleaner and added straps but it would not be as sturdy as his tote. I’m VeRY pleased w the product!
Nice rigs guys. I do have to say, the running stroller with the bigger wheel, make it easy to move around. It has lots of space underneath, for air bottles and extra gear.