I started out hand pumping my Marauder pistol and it was pretty easy. Less than 50 pumps will fill it giving you at least a couple dozen consistent shots. Then I got an Avenger which takes a lot more strokes and it wasn't as much fun. So I got a YH (Yong Heng). But it is noisy and I didn't like running it every time I wanted a refill so I got a used SCBA tank and fill set. I still do not have a little DC powered compressor but may get one someday. When I go to the range I just carry my SCBA tank. To me the optimum is an air tank and a compressor that will fill it. But that will cost at least as much as a Marauder. A little DC powered pump would cost less but it isn't going to be as quiet as a SCBA tank and it is going to take a lot longer to fill your gun. Just a YH will fill your gun fast regardless of the size of your tank but is not easily portable.
Comes down to how much you want to spend. Hand pumping is the cheapest and the second quietest. I keep my hand pumps as a backup. If my compressor fails, I will hand pump until I get it fixed (or buy another). I also took a hand pump to the range once before I got the SCBA tank. They are very portable.