The smaller the vehicle, the lower you will need to sit for stability. 4 wheels are usually more stable than 3 and a long, wide 3 wheeler will be more stable than a short, narrow one. Make sure the batteries are well forward so the centre of gravity is near the centre of the machine - a heavy golf bag on the back can make a bad machine tip over backward if you accelerate fast up a steep hill. Steering Some vehicles, especially those by new manufacturers, tend to have very poor steering. Also, with a three wheeler, does the front wheel hit your feet when you go to full steering lock.
Most golf buggies do have reversing.
Manufacturers seem to thing they cannot sell a vehicle without reverse. A controller with reverse is about twice as expensive as one without and this will add to the machine's cost. If they do, then try the effect of operating the reverse switch when you are travelling at full speed. Some inferior controllers cannot take this and will blow up. There is one machine of Polish manufacture which has the controller mounted very low, between the back wheels.