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All of these toys are expensive. The most expensive piece is the one you end up putting up for sale, or into your closet, so keep doing what you're doing before making the purchase.
Wait until you start thinking about computers!!!
The Back Plate/Wing (BP/W) form of the buoyancy control device (BCD) is the only acceptable approach from some people's point of view. I have one (DSS), I like it. I also dive with my jacket style because that's what our students use, and I don't want to confuse them. I also don't want to jeopardize the relationship I have with the LDS owner, who sells jacket-style BCDs. Nothing fundamentally wrong with either, and you don't run across dead divers littering the oceans because they weren't wearing the "correct" bcd.
If I were starting, I'd look seriously at a BP/W for a lot of my own reasons, but that is me.
About weights. When I bought my BP/W, I was carrying 6 pounds in fresh water, 10 in salt. I'm now not carrying any weight in fresh water, and only 4 in salt with a 3mm suit. So, until you get to diving with a dry suit, you shouldn't worry too much about weights. Belts are simple, and cheap. You can always find lead to fit them.