Unless you are going to use this pump in a location where there is a dependable source of compressed air, I would recommend the electric start. Electric starting systems have their own peculiarities, and problems, but the electric systems are easier to recover and bring back up to starting voltage. Hauling a new battery to start the pump is easier than hauling a compressor. Batteries are affected by temperature, but so are compressed air systems.
I have seen both air hoses and electrical lines strung out long distances across expansive parking areas for air start vehicles which would not "bust right off" in sub zero weather, while merely a jump start from a pick up truck would have sufficed for an electric start vehicle.
I have seen air started, "black start" (air started diesel engine cranked) gas turbine black start Frame 5 size peaking units which could not be "black started" until a portable compressor was located (from the water department, in the case of this municipal electric utility,) and hauled to the unit, and jury rigged, because the air system at the plant went down when the system went "black". (I put it in the black, while running tests, unfortunately)
rmw