What about small things such as where to clip your SPG, Octo, Reg? Where to put weight pockets?
I'm thinking:
HOG #32 Wing
Dive Rite Aluminum Backplate
Dive Rite Deluxe Harness
2" crotch strap
2 Cam bands
4 sex bolts
What is the best way to weight yourself using a BP/W setup? I was thinking a pair of XS Scuba QR weight pouches attached to the harness with keepers. Any other suggestions? (no weight belt)
I agree, it would be good to have more information about the diving conditions you expect to encounter the most, as that will drive your equipment choices. For example, will you be diving in a local environment with cold water with a single Al80 tank? If so, that will entail a thick wetsuit or possibly a drysuit, which would be an argument for a steel backplate: you can carry lots of ballast on your back and maybe even negate the need for additional weight. Conversely, if you plan on diving in warm water (3 mm wetsuit) with a steel tank, you may be overweighted with a steel backplate, and prefer an aluminum plate. These are just a couple of examples (admittedly, they're polar opposites) of how much your regular dive conditions will influence your equipment choices.
Your wing size will also be dictated by environment. If you're diving with a thin wetsuit and carry only minimal weight, then you can get away with a wing that's smaller than the 32 lb HOG you mentioned. On the other hand, if you're using a thicker wetsuit or a drysuit and plan to use a steel tank, you'd probably be better served with a 30 lb singles wing or slightly over. Wing manufacturers are usually really great about advising you on the optimum wing for your needs. Give them an idea of the equipment you plan to use, and they'll have a better idea on what to recommend.
I carry all my weight on my back plate and don't need additional ballast. It works well for me. If you to try and do the same and decide to buy a steel plate, you can find a plate that's weighted to meet your needs. Manufacturers like Deep Sea Supply offer 'inserts' that fit on their plates for extra weight. Other manufacturers like FredT can provide a heavy steel plate in one hit. If you go the aluminum route, you can carry additional weight via a pocket affixed to your cam-band, which will also serve as a trim weight. Wonderful for helping you dial in your trim. You can also simply thread weights through the waist-band of your harness, if you desire. Then there's the option of a DUI weight harness...you have multiple options from which to choose.
I clip my SPG to my left hip D-ring via a bolt-snap. I use a 5-foot long hose with my octo bungeed around my neck. If you favor a recreational primary regulator (the hose is about 30") and a 40" octo, you can easily affix an octo keeper on your right chest D-ring and shove the octo's mouthpiece in there for easy access. It looks tidy while still providing good access for a buddy.
You can thread a cutting tool on the waistband of your harness, or buy a pocket to thread through the waistband, and clip off various items in there. You can also affix thigh pockets to your exposure suit for 'storage'.
Expect to tweak your set-up for a while...it may take a dive or five to adjust your harness to fit exactly the way you want it. Once you do, though, you'll never need to touch it again. You'll also need a few dives to figure out what works best where (do I like my knife there? My light there?). It's all part of the fun, though.
Hope this helps. Good luck!