Different Types of Automatic Guns and Pistols
The Colt Gold Cup is popular for NRA bulls eye shooting, custom guns are popular for action shooting. Of course, both of these are fairly expensive. I use several Auto Ordnance 1911s, each customized for the particular type of shooting. It is not difficult to do the customizing yourself by buying parts and kits available through ads in shot gun news.
The .40 only due to the fact that it is easier to find high capacity pistols in a 40 than 45 but- I understand your response and consideration of same. I have no problem with the 45, but some shooters have a problem shooting them so I usually split the difference and recommend a 40. I am a believer in spending the money up front for a quality firearm for many obvious reasons. The large magazine capacity and $700 cap eliminates some of our options.
All is not lost however. One such pistol that I know of is made by Kimber (I've previously written glowing reports about their products in the past) and is meets both of your requirements. The Kimber Ten Series has a 1911 frame that holds a ten round magazine. Additionally, there are (where legal) 14 round magazines for sale through Kimber Master Dealers, and Kimber Custom Shop. They are the same length as the standard magazine and fit flush with the bottom of the grip.
If I were to make a second choice it would probably be the Ruger. I've never been overly impressed with the Taurus but that's just a personal preference I guess. For the money they are functional/dependable but I still think your best value (and potential for highest resale if you ever want to do so) is the Kimber.
I will admit to a bias against the Jimenez 9MM. In my opinion there are other pistols available at around (or slightly higher) the same price. This does not necessarily mean that your experience with the pistol will validate my bias. It is possible that you will shoot it and have no problems.
In short, I no of know particular reason that your use of the Model J.A. 380 should be unsafe. I would however put a considerable amount of ammo through it at the range prior to carrying it for self defense. If there is any kind of problem, you don't want to find out at the "moment of truth".
I can tell you in advance that you are probably going to find certain ammo that the pistol doesn't group well with, and still some that may have feeding problems. So you are going to want to experiment with those two issues regardless of any potential malfunctions. If it is going to present itself, it should do so while you are narrowing down your choice of ammo based upon performance.
As far as I know the Jennings 9mm is about the same as the Jimenez 9mm, and not terribly good. A talented gunsmith might be able to get it back into working order, but aside from that I'm not completely sure. Those guns just weren't designed to weather repeated firings. You may end up having to invest in a new pistol.
I feel your pain, I was sold a Jennings J-22 several years ago and the thing promptly shot itself apart, and that was just a .22 LR! It's in pieces in my gun safe waiting for the next $50-a-pop gun buy-back sponsored by the Detroit Police Department. These firearms were of questionable quality when brand new. They were probably one of the lowest priced new handguns that could be found and the poor quality explains it. The original manufacturer went into bankruptcy as a result of losing a $24 mill lawsuit due to a design flaw.