Hi K ~
I am happy to post an answer to your question. Welcome (I think) to the world of diabetes. It is a lifestyle that is unique and is, and always will be, a very unique part of you.
Now, on to the pump. For me, going to a pump was life-changing. I live an active life as well, and pens were not always convenient to use, My A1-c was high and my kidneys were showing signs of wear.
I chose an Animas Ping pump. I believe the Animas is the only pump that is advertised to be totally water proof. I don't know of a waterproof case that is available for any pump. With a tubed pump, you can take it off to shower, swim, for intimacy, etc. In doing so, you will need to learn what your body does to itself without insulin, such as highs. Usually, it is not recommended that you are not off the pump for over an hour. I don't swim, but I have a friend who also has an Animas pump who regularly swims and tubes down a river with her pump in place. As for the infusion set, when the pump is disconnected, there is a cap that goes on the infusion set for protection, It is easy to put on and take off. Animas uses the Dexcom Continuous Clucose Monitor and I understand that is is very good, although I don't use one, so I can't comment on its effectiveness.
As far as I know, the MiniMed is only water resistant. The MiniMed infusion sets also have a removable lock on them and a cover for shower or swimming. MiniMed uses their own integrated CGM, and I am sorry; I don't know anything about it. I believe the numbers you ask about are pump model numbers, and are no longer made.
I liked the Animas because of its communication with the meter, its fail-safe operation, its colour screen and its computer software. Their customer service, for me, is second to none.
Best of luck in your decision, both to pump and in your choice of pumps.
Keep in touch, let us know how you are doing.
Sometimes, it is good to be diabetic! Be well.