With the right ammo, you will do fine with a barrel shorter that 4". As a general rule, these short guns would do better with 124 as the "heavy weight" 147 much better in longer barrels, which are not a problem unless you are concealing it. then the question is a choice you must make. In that case, I chose the Glock 17 4.5 inch barrel. In retrospect, maybe the 19 or 23 I think right at or just under 4 inch barrel, with 9mm conversion barrel may have been a better choice for me.
I considered a Solo, but ended up with the S&W Shield, which conceals easily. Less than 1 inch thick, also available in .40.
You might also consider .45, Glock 30, 36, 30 SF, or 30S are great choices, as is the Springfield arms XD in .45 Here I chose the 30S...surprisingly accurate. The XD is way flatter, easier to conceal. I have heard nothing but raves on the 9mm XD, It was Recoil magazines choice a while back when they reviewed the .45 version, they could not say enough good about it, despite a recall that was on at the time.
Yeah, I am kind of a Glock guy, but remember...if the gun does, heaven forbid ever get used in a self defense situation, it will sit in evidence for a while. for less than 600 you can replace most any Glock, Kimbers are more expensive, as are others. I sure did like the looks of the Solo I saw, I think that particular version was just over 800 at the time. Beautiful gun.