Since your lugging out lots of weight, over uneven and perhaps rocky ground, I would recommend the TWO wheel variety....
IMHO - YMMV.
I tried the 2 wheel style game cart before. Borrowed one from my brother that was kind of like a dolly with smallish bicycle type tires on it. It really sucked going up a steep incline with an elk quarter on it...Snagged on every rock and stick, had to lift it over deadfalls, didn't seem like it was better than just packing it out on my back...It was great on level ground though...
I was thinking the advantage of the one wheel style is that it might be easier to maneuver through the brush and around the rocks...But, not sure if their is any advantage as I have never used one.
