I can suggest a JD Gator 4x2 or 6x4, pre 2005. Not fast, not sexy, but can haul materials. Dif lock on the 4x2 and its stable and goes through mud, you can even turn a little. My 6x4 with the dif lock on? You are going straight, only straight, and straight until you take off the dif lock. I load the bed with almost a yard of wet clayey sand with my RC 30 taligate down, and it hauls it no problem, and dumps with an inexpensive electric actuator I installed.
My 4x2 has 4550 hours on the original 10hp Air cooled single Kawi Fe 290, the 6x4 has 450 hours, liquid cooled 2 cyl Kawi FD 620. They are not for sale. I keep an eye out for 1999 to 2004 models on various places, The newer faster machines are not worth the money, and not nearly as durable. The ONLY downside is JD parts are expensive.