Welcome from Sparks, NV. I, too had the same problem when I got around to purchasing a .45 which I carried during the early 60's. However, when I went to my LGS, I found it to be too heavy. I had read about the Ruger P345 and found it to be more manageable. I also started purchasing various firearms in different calibers. One that highly appealed to me was the Browning Hi-Power in 9 mm, I know, I know, some might call it blasphemous, but it worked for me. I was lucky enough to get a MK III shortly before they were discontinued. I liked it so much, I came across a used one, albeit a 'C' model. Then most recently, came across a new, from Israel, a Masada 9 mm what holds 17+1. Couldn't ask for more. The Masada is small and light, accurate and from what I have read, reliable. Being older, one might have to change what one carries when they were younger. Whatever you decide! It's your choice and Good Luck to you and Good Shootin'
Forgot to mention: Got my Masada for less then $500 out the door.