That’s a good set up. There are a couple of real advantages to diving with a BP/W, and this applies to all levels of diving. One, the rigid plate basically couples the tank to your back, spreading out the point of contact. Think of a tank rolling around on the floor, then imagine a flat(ish) plate strapped to it, and now the tank is much, much more stable on the floor. Your back is kind of like the floor. Two, you don’t want clutter and excess fabric, plastic, padding, whatever on your chest and torso. Trust me on this one; life is very different in the water, horizontal, and you will be more comfortable with less stuff on your body. The simple webbing harness achieves this. Three, you don’t want excess buoyancy, which you then need to counter by adding weight. Virtually all jacket BCs have inherent positive buoyancy and this is counter productive to ease of diving, descending, adjusting to changing depths, etc.
Big sincere congratulations on losing a large amount of weight! Another nice thing about the BP/W set up is that as you shrink, you can simply re-adjust the webbing harness and cut off any excess.
I agree with many of the comments on this thread about not buying gear now, and waiting until you finish your class. When it does come time for you to buy a BC, you should absolutely try a BP/W before buying anything. There are some recreational instructors that mistakenly say BP/W is only for technical diving, but keep in mind many OW instructors are also tied to the gear sales industry that is pushing jacket BCs, and many simply lack the experience in other types of BCs.