I just bought my first BPW and went through similar tasks / banging head against the wall over the sheer mad amount of options and customizability of it all. I ended up buying the Xdeep Zen simply because it was readily available at a very good price and I knew others who dive it and had a chance to have a look at it in the wild as it were. I was originally going down the route of a full custom system, but ended up confusing myself and overthinking the whole situation. Id go to a shop if possible, try what they have available. If you find a comfortable fit and its a good price go for it. You can custom it as time goes on and you get used to the pros and cons of what you bought. Have done a few dives with my zen system now and still learning what I like and don't like at the moment. But buying a completed system saved me a royal head ache as I noted earlier I was over thinking the whole thing and confusing myself. Good luck and they are worth it