I own two 2009 Yamaha electric carts. My intention was to put lights and s rear seat on both, taller tires on one and leave it at our mountain house. After trying one in the mountains, I think a gas engine cart would work better on the steep gravel roads. I have yet to buy the lights or seats. My grandchildren like to cruise around the neighborhood in these and to the pool in the summer.
EZGO and ClubCar are about equal and have the greatest number of accessories available. One has steel frames, the other has aluminum frames. The Yamaha electric models are set at 12 mph and can be boosted to 15 mph; the other two models have a third speed setting. None of the golf carts have the suspension or brakes to safely exceed these speeds. The comptrollers can be changed out for more torque if the owner wishes to add a lift-kit and a larger wheel/tire package.
I live less than five miles from four different cart dealers; carts are popular and pricey here. You can honestly buy a nice used Jeep for what some of these carts cost.
A word of caution, if you opt for a limousine cart (six passenger). Some of these types are full frame and some are kits where the original frame is cut, kit welded into it to lengthen it, then re-assembled. The kit versions do not hold up so well.
I believe forum member Engineer1911 retired from EZGO or ClubCar, contact him.