mfer
What kind of pistol work? I would pick up Patrick Sweeney's Gun Digest guide to Pistol and Revolver gunsmithing as he lays out the basic tool set and explains the whys of his choices. He also does a good job in separating out what an amateur should be capable of and what jobs are best reserved for advanced hobbyists or skilled gunsmiths.
There is a reason that Brownells has pages of hammers and punches. Different jobs are best served by different tools--you can try using just one hammer for example but it will be optimal for some jobs and sub-optimal for others. You can say the same about punches as well. If you asked me in general, what sort of punch and hammer should be bought, I would ask you what task that you plan to do.
One last thing, easily overlooked, using a hammer and punch requires eye protection as metal splinters can be propelled at relatively high speed when you are hammering on a punch and a pin. If you wear eyeglasses, be sure that they are impact resistant and cover the eye socket thoroughly.
Good luck and be safe.