Stylistically, I would go with Brazilian Jiu-Jitsu, the emphasis on the ground does keep it safer. In fact American Folkstyle Wrestling has rules that encourage more matwork to reduce the risk of injuries during takedowns, which is where most wrestling injuries occur (I can dig up a source on that if you really want, but it'll take me a fair bit of time). Kosen Judo, which is really best described as Scholastic Judo similarly has rules encouraging more time spent on the ground, likely for the same reason.
The finding a good school bit is really prevalent here though. The meathead factor will be a big problem, and I've actually spent quite some time talking to people I know who have gone to various schools to figure out which one is the safest. It has more of an emphasis on drilling techniques than on sparring, which should control the risk of unexpected injuries better. The instructor is also a locally certified group fitness instructor, which isn't mandatory for MA instructors here, but looking into whether the instructor has credentials specifically relating to teaching, and not just subject matter expertise would be a good idea.
For striking, I would lean towards boxing. The main reason being that boxing has far better protective gear than any other style. If you really want to protect your hands, there isn't really anything that comes close to Winning MS-600 gloves (and certainly nothing to protect your elbows or knees that's in that protective category, or even a few orders of magnitude down), the same goes for sparring, Winning FG-5000 headgear is about as protective as it gets, but not really appropriate for sparring that includes kicks as the facebar obscures vision. The down side is you'd end up spending near $1000 on all that stuff, but if you have the money I think it's a great investment, just like spending $150 on a custom mouthguard instead of a $40 boil and bite.
As far as important qualities for a striking art goes; learning how to hit hard, sometimes sparring near 100%, and includes punches to the head, boxing has all the basics covered. The most common striking attack you're likely to face is a punch to the head, so it's very useful to know how to slip, block, and parry it. Whether you are taught to rely too much on the gloves to act as shields would depend on the instructor. Ideally you'd find one that can teach you in multiple styles of boxing, and you can tell him that you're interested in self defense more than competition and get your advice tailored to that.
I can't think of anything that incorporates both grappling and striking, that has a low risk of injury, and is something I'd want to rely on while bouncing. To get both I think you'll have to split it up. A Jeet Kune Do school might work, although it's much harder to really predict what a JKD class might be like. Some of them go much more boxing like, while others go much more Wing Chun like, and I wouldn't be surprised if there's people using Muay Thai or Karate as their JKD base as well. You might find that you've got boxing-like JKD that lets you benefit from the great boxing protective gear that doesn't teach grappling, or you might also find a quite suitable one that teaches BJJ with a focus on safety at the same location.
I'll talk around to some of the older wrestlers that I know and see if there's a chance that Greco-Roman Wrestling is less injury prone than Freestyle Wrestling or Judo. If it is, I think it would be a good idea to do as well. I don't think there's a safer default strategy than shutting down your opponent's attacks with a strong clinch and talking them down until they decide they don't want to fight that much after all ("I'm too old to be getting into fights anymore, let's not do this, OK?"). If you end up getting hurt training though it's pretty counter productive.