I have much experience with Ruger firearms and can say w/o reservation they are very fine pistols. They are affordable, reasonably accurate, durable and extremely reliable.
The P-93 would be an excellent choice.
I now own a P-97, their polymer/stainless .45acp offering. They are easily field stripped for cleaning. I opted for the P-97 because I am a big fan of the .45 over the .9mm or the .40S&W and in my opinion it fits the bill for my kind of shooting.
Ammo can be had cheaply, it can be reloaded cheaply. You can have full house loads or reduced power loads for target shooting. Not that you can't do the same with the other 2 cartridges, but if I have to make 1 shot count, I want 230gr's of hot lead and copper not 115-140, flying in the direction of the threat.
The slower velocity of the .45acp also lends itself to inherent accuracy, and IMO a more managable pistol overall.
Outside of the Ruger family of firearms, you may want to consider a 1911-A1 style of pistol, as they offer more options to customize the gun to your personal liking.
A base model of 1911 can be had for the money you are willing to spend and would make a fun hobby to customize. Good Luck