You might want to read this so you understand how tubeless compares to a tire with tubes.
https://www.bikeradar.com/advice/buy...ides/tubeless/ Notice that you may not have to replace the wheel as long as you can get your existing rims to seal with tubeless rim tape. That's a lot less expensive than changing wheels. Should you decide to use tubeless ready wheels, take in your existing wheels to any bike shop or to the REI store they will give you the equivalent wheels and switch components (the cassette on the rear wheel).
I live in goathead country too and after a few really bad encounters learned to recognize the goathead plant and avoid them. Out here they grow at the edges of the road and bike paths. It was mostly riding over the plant that got my tires. It's a lot harder to avoid tumbleweed than to avoid the goathead plants. I carry a pump and spare tubes whenever I ride. I do my own repairs so fixing a flat costs pennies, not dollars. It is too much trouble and potentially dangerous in the heat to not fix the flat on the road. My only encounter with tire sealant was on a friend's SUV. What a mess to deal with a damaged tire that had sealant in it. I don't use it in my regular tubed tires.