While I don't ride in goathead territory often I have done some riding there and can tell you without equivocation that gatorskins will puncture from a goathead easily. GP4000s easier...but goatheads are pretty nasty. Marathon Plus is probably the best tire and will feel a lot nice than using Mr. Tuffy in my opinion but a good tubeless tire with an adequate amount of filler juice is the best of both worlds. One time in Albuquerque i got home and found 4 goatheads embedded in my tires. I pulled all four and spun my tire around, seeing each hole weep some juice for a few moments and then...nothing. Done. I lost so little air I didn't even have to pump my tire up. I have Bontrager R3 tires which aren't quite as supple and nice as 4000S, but much better than Marathon Plus. If you choose to go Tubeless you may have to get new wheels. Mtn bike tubeless can be done with many wheels not made for tubeless but not so with road wheels. For thorn country I would highly recommend tubeless. Just be sure you are familiar with changing a tire if you get a bad hole...using a tube when needed, etc etc.