So, for a question you asked that has had answers hinted at but not fully answered: Types of harness
There are three main types of harness: Hog, Deluxe, and Soft.
Hog has been described. It's a single piece of 2-inch webbing with no padding, no fancy bells and whistles and doo-dads. This is what most people end up preferring because they find out that there's nothing to cause unnecessary buoyancy, it's the cleanest setup, and it's comfy enough that padding is pointless.
Deluxe is similar to the Hollis Elite 2. Practically every brand has one. It's comprised of several pieces of webbing. Typically one for your shoulders down to clips between your shoulders and your waist. Those clip into pieces that go to plates that run to your waist belt. Your waist belt is a separate piece of webbing. These are adjustable, padded, and have clips. These also typically have two d-rings per shoulder compared to the 1-per of DIR/Hogarthian setups. These are marketed as comfier, better, and easier. Some people prefer these, but I've yet to see a reason why....other than shoulder mobility, but I'll explain the fix for that in a second.
Soft is probably a bad term for it, but it's a soft backplate. The most famous is the Transpac. These typically have a "deluxe-style" harness built in, don't require a backplate, and are marketed as the comfiest by-far. I believe most can accomodate adding a hard backplate. IMHO, if you're getting this you had might as well get a poodle-jacket. It's nothing but soft, buoyant, padding that is completely superfluous.
The "fix" for shoulder mobility on a hogarthian-type harness comes in two forms: Adjustable harness or custom buckle. The custom buckle is sewing in a custom buckle on one side of your harness. I suggest keeping your fully Hog-compliant setup the same in every way, except you split the webbing between your top and bottom connections on one side somewhere near your rib cage and add a heavy-duty buckle there by sewing it in. That way you can get out of it more easily on land (if your shoulder mobility is limited) by simply unclipping one buckle. The other one, which I like better, is the "adjustable" harness. I first saw it on the Hollis Ride, but I believe the Halcyon Cinch system is the same idea. On a hogarthian harness, your shoulder straps ARE your waist strap, so these "adjustable" ones allow you to tighten your shoulder straps down by pulling the slack out and into the waist strap area....and then loosening by adding slack to the shoulder straps by pulling it out of the waist strap area. I'm still playing with an idea about how to add it to any system, but we'll see how that pans out
One last comment on the back pad. It's not necessary for comfort. I spent a lot of time DM'ing pool sessions in swim trunks or a 2mm shorty, and the BPW was fine. It is surprisingly comfortable, as it spreads the weight evenly over your back. I want a backpad on mine (haven't bought one yet) JUST for the storage pouch for a lift bag. I think that's a really cool idea. Other than that, don't waste your time/money on one.
Overall, the general consensus that there's no "entry-level bpw" is a good one. The nice thing about the BPW is that anyone can dive one, and it can grow with you as your diving progresses. It's a simple, clean, efficient system that reduces clutter and waste in an efficient way.....as long as you set it up that way. People add hundreds of pockets and QR weight pouches and all these other bells and whistles that add up to a poodle jacket.
Get yourself a Marseilles-style weight belt (it's rubber, mostly used by freedivers, and uses a buckle like most belts instead of like your waist strap on your BPW) and a stainless plate, a steel tank, and some weight plates if you need that much weight. Remember, though, that you want SOME weight on yourself so you're not SUPER buoyant without the BPW itself (balanced rig concept).
