Bob Greene,
You cannot listen to any one person here. So, let me summarize the key take away points.
1) From Stick: The big problem is finding a car that drives as well as it should in the first place. 90% of them have not benefited from meticulous and knowledgeable maintenance combined with a willing owner and so performance will not be optimised. Boy, is that ever true. I'd suggest even greater than 90% in the ones you'll see for sale. A well-sorted car is always better than one needing work, so look long and hard.
2) From Thelews: the highest quality 113 you can find, afford and enjoy will be your best bet. Again, sage advice. If you don't know these cars, you'll need to look at a lot of them to make that determination.
3) Standard or automatic? Well, that is purely up to how YOU want to drive it. I put about 2,000 miles a year on my car and it's automatic. Perfect? No. But when I get stuck in some kind of stop and go, or traffic, I'd sooner get out and walk if I had a standard. But others live by the vroom shift vroom feel and sound, others spend all kinds of time and dollars on standard transmission conversions, etc. so really, it is all about your personal feel. You will find a lot to like and something NOT to like about any car in any configuration.
Your purchase will be something to bring you joy, so figure that out after looking. Maybe it will come down to color; maybe to a working a/c unit; maybe to the slightly more lavish chrome trim on a 230; maybe to the "cleaner" look of a Euro model. You will NOT find your answers here, just some guidelines so when you do go looking, you'll know a little bit about what you are looking at and for!
Good Luck!