The proper battery type is 24F. This has the proper orientation of the positive and negative terminals.
There are only two manufacturers of batteries in the US, Exide and Johnson Controls. I recently purchased a Champion battery from the local auto parts store, I took the decals off, and with the help of my friend mrfatboy, painted the top cell covers black and fixed a round "Varta" sticker to the side. Voila, done.
I did have to "adjust", that is trim off a bit of the formed plastic piece around the top of the battery where the carry strap fit into, but it is a non-structural part of the battery. With that done the battery fit into the allotted space like a glove, and with the proper hold down.
There has been a lot written about the battery options. I would suggest you use the main search function (the one in the string of items starting with "Home" , not the one in the top right of the page (it only searches the current forum group you are on, not the whole forum).
Some have found black cases to put a get battery in, some have purchased the MB battery from the dealer. Some of that depends on whether you show the car.