Welcome! The Kel-Tec is a serviceable little pistol. It's pretty bear bones defense, but can be reliable. Not what you will enjoy shooting much as the range, though. You should shoot both and see which one you like best.
I used to own a P-11 Kel-Tec. I carried it for a few years and it was a nice little gun for the money. I installed a trigger shoe which made the trigger pull length feel shorter and a lighter trigger spring as well. I also smoothed up the internal metal parts. These changes made it better. They do not recommend shooting +P ammo in this gun, at least not back then so you would want to stay with the standard pressure stuff. Lots of good choices here so that's not a problem.
If you can go up in price a little more, the M&P 9c is a very nice choice. But there's nothing wrong with the P-11 in my experiences with that little gun.
I have had the Kel Tec in both the PF9 and two different P-11's, and out of the two of them, I had the P-11's the longest. I have large hands, and the PF9 just plain ol' beat me up too bad, so I traded it off on the second P-11. I never have had any issues with any of the three, the the older P-11 has had about 800-900 rounds put through it...still runs strong.
Just like said above, you really don't want to run +P ammo through them. They are not that kind of gun, but for the niche they were designed for, they do a good job.
I did order, and install, the steel guide rods for the P-11's. Not that I noticed any real difference in how the gun shot or anything, I just wanted a spare. You would not be wasting your money on any of the Kel Tec pistols, in 9mm. Good luck on your search!